DUBLIN — For Conor McGregor, it all started when his sister told him about The Secret.

Erin McGregor had received a copy of the book from a friend, and she liked the things she read. She liked how the book told her that she could take control of her life. As a fitness model and bodybuilder, she was no stranger to discipline. She’d crafted hard, rugged muscles through years of self-control and hard work.

But the book told her she could take things to another level.

She enthusiastically told Conor about the book. Written by Rhonda Byrne and released in 2006, The Secret is based on the law of attraction. It tells the reader that the power of positive thinking can change their life and bring about anything they desire: money, wealth, happiness.

At first, Conor thought his sister was being ridiculous. The law of attraction? It sounded like a bunch of nonsense.

But one day, a year or so after Erin first told him about the book, Conor had a bad day. He remembered the book and how Erin would go on about it and decided he'd give it a look, even if it felt a little ridiculous.

It was also available in DVD form, so Conor and his girlfriend Dee obtained a copy. They sat down and watched it. At first, Conor felt it was what he'd originally thought it was: "Even when I first watched it, I was like, this is b------t," he says. "But then something clicked for me."

He realized that the things he focused his thoughts on, whether bad or good, usually came true. And so Conor and Dee started practicing it, figuring there was no harm in at least focusing their thoughts on the positive.

They started concentrating on the things they wanted. At first, they focused on small things. They would drive to the local shopping center and focus on securing the parking spot closest to the door.

"We would be driving to the shop and visualizing the exact car park space," he says. "And then we’d be able to get it every time."

They kept visualizing small things, seeing the law of attraction play out in front of their eyes. Eventually, the small things turned to big things: dreams of wealth, success and fighting championships.

Today, Erin says she believes Conor always had the ability to control his life with positive thinking, even as a child. She believes it was always buried inside him. But his father Tony says there was nothing remarkable about him, nothing that would lead you to believe he would eventually become what he is today.

But everyone, from Conor to his parents and sister, believes that the moment Conor watched The Secret was the moment everything changed. This was the moment he slowly began to morph from a quiet boy into a brash and confident man, a man who spoke about the things he wanted and then went about the business of obtaining them. This was the moment when the dreams of a world championship, of financial windfalls and fame beyond measure began to take root.

This was the birth of Conor McGregor, UFC superstar.

McGregor is a fighter, but the fighting world is filled with those, though he is perhaps better than a great deal of them.

What sets McGregor apart—and what has made him a rich man with the promise of even greater riches on the way—is the force of his personality.

He is a quote machine, always good for a headline. He says things few others in the sport of mixed martial arts will, and he takes direct aim at current and future opponents with a razor-sharp tongue.

He inspires fervent devotion from his fans, especially those in Ireland who have watched him since long before he made the jump to the UFC. He creates a palpable sense of hatred from those who believe he's too full of himself and has been given too much, too soon, simply due to his mouth.

But it is hard to paint McGregor with the same brush as other mixed martial artists who rose to fame because they could talk a good game, mostly because he has backed up everything he has promised so far.

We now view McGregor, who will fight Chad Mendes on Saturday in Las Vegas for the interim featherweight title, as one of the UFC's biggest stars. But how did he get here? Is he playing a character like so many others? Is he truly as confident as he appears to be?

Tony McGregor, the child of an Irish father and English mother, began his life across the Irish Sea in Liverpool, England. But his family split up when he was seven, and Tony was sent to live with relatives in Dublin.

Tony met Mags at 15 years old. They were walking to school, and they crossed paths. A year later, they both landed jobs in a local factory, and a romance sparked. They were married in 1980, when both were 21. Erin was born a year later, and Conor came into the world on July 14, 1988.

Tony and Mags were from the working class, and so they went to work, scraping together money to buy their first small house in Crumlin, a suburb of Dublin. They couldn’t afford a house in the neighborhood in which they’d grown up, so they purchased a two-bedroom house in a different neighborhood. They stayed in Crumlin for 12 years.

As with a hefty percentage of European kids, Conor's first sporting love was football. He was a Manchester United supporter and played for a local club. But there was a boxing gym next to the football club, and it piqued Conor's interest. He would occasionally pop into the boxing gym before and after football practice, but that was the extent of his interest.

"I was really focused on football," he says.

When Conor was 15, however, he experienced a life-changing moment. The family moved from Crumlin and settled in Lucan. You'll find Lucan on the far outskirts of Dublin, out where the hills turn green and roll and remind you of the Ireland you see in travel advertisements. They settled in a narrow house in a quiet neighborhood, where every house is separated from the road by a white picket fence.

The move was painful. Conor was ripped away from his lifelong friends and deposited in a new neighborhood filled with kids he didn't know.

"It's difficult for a teenage boy to be taken away from the only thing he knew," Tony says. "It was a different area, different friends."

"I certainly did not handle it well. I eventually did. But at the time, I had a lot of resentment towards my family. I actually was really upset for a long time," Conor says.

Things were awkward. But he believes the exile actually helped mentally prepare him for what would eventually become his life.

"In the long run, it ended up working out better for my career, because I ended up being isolated. I ended up alone with my thoughts a lot more," he says. "I feel being alone with your thoughts is a good thing. It allows you to figure things out for yourself. And that’s what happened for me in Lucan."

Lucan also helped connect him to new passions and interests. He began kickboxing, which made him take boxing more seriously. Instead of following the same trail as every other Irish boy, Conor began to blaze his own.

"I realized I was enjoying combat sports a lot more than I was enjoying football," he says. His love for football slowly began to fade, and a deep appreciation for combat sports began to take root. "Instead of going to the football club, I would go next door to the boxing club."

Conor kept taking boxing and kickboxing classes, but he also discovered jiu-jitsu.

Slowly, the pieces to his future in combat sports were coming together.

Irish culture dictates that if you are not interested in school—if you have no desire to make your way to university and secure a degree—then you find a trade and you begin your working life.

This is what happened for McGregor. He had zero interest in furthering his education. "I had no use for it," he says. His mom says he had the intellect for academia but just didn't have the interest.

He wanted to focus his time on training. But he lived with his parents, and they insisted he find a trade and a job.

He did, taking a job Mags found for him as a plumber. It offered a comfortable living, and with hard work, Conor had the opportunity to make a lifetime of decent money.

But he hated it from the beginning. It was grueling work. Conor looked around at the people he worked with and saw the effects that years of manual labor had on the body. He saw the stooped postures and the dead eyes.

"I did not see anyone that was in any kind of healthy shape," he says. "I saw that maybe if I walked away from plumbing I could train two times a day. I could really focus on my diet. It’s hard to focus on your diet or on training when you’re on a building site 10 or 12 hours of the day."

He continued to train as often as possible while maintaining the job, because that's what was expected of him. Mags would wake up at 5 a.m. to take him to the construction site, just as she'd woken up early to take him to Sunday morning football matches when he was younger.

He worked 10 to 12 hours each day and then went straight to the gym for training. He fought on the weekends. He wanted to be a high-level fighter.

But such a schedule is incredibly demanding on the body, and Conor found it impossible to maintain. And so he made a decision: He was going to quit plumbing and focus on training full time. But first, he had to tell his parents.

"That’s it. I’m not going anymore," he said.

"You are going," they said.

A heated argument ensued. The way Tony remembers it, he and his son nearly came to blows. He and Mags were skeptical, because fighting for a living sounded like a bunch of nonsense.

"The first thing they said was, 'Who else has done it? What other Irish man has made a career of this?'" Conor says. "And I could not point to another Irish man who had done it, because there was no one before me."

Still, he'd made up his mind, and he was sticking to it.

"You’ll be sorry when I'm a millionaire," he told his father. "I remember saying, at 25 years of age I will be a self-made millionaire. And my father laughed at me.

"And you know, I was a year late. I’m 26 now. But I did it. I told him so."

Tony concedes that Conor did, in fact, tell him so.

"He would say, 'I'm going to be famous. That's who I’m going to be.' He and Dee would sit there and watch the fights," pointing to the television in the McGregor's living room. "He'd say, 'That’s where we’re going to be. We’ll be in America this time in a few years.' And he's there now."

McGregor made his professional MMA debut on March 8, 2008. When watching footage of those early fights with head coach John Kavanagh at Straight Blast Gym Ireland, it is easy to see his potential was there from the beginning. But he was raw, wild and untamed. He went 4-2 in his first six fights, showing promise but also holes that needed to be filled.

He worked relentlessly on filling them. He constantly badgered Kavanagh to open the gym at all hours of the night, which prompted Kavanagh to give him his own key so he wouldn't be woken up by phone calls in the middle of the night. McGregor is still the only fighter with his own key to SBG.

He grew obsessed with movement, with stretching and physicality. He woke up each afternoon (he is a legendary late sleeper), crawled out of bed and began stretching. He did bear crawls around the house. He practiced jiu-jitsu and striking against invisible opponents.

And beginning with his seventh fight, something clicked. He knocked out Hugh Brady in just over two minutes.

His next fight lasted 16 seconds, another knockout.

The fight after? Just four seconds and another knockout.

His win streak grew, and his fame—driven by his natural charisma—began spreading beyond Ireland. UFC President Dana White began to hear rumblings about McGregor; the Irish fans were adamant that the UFC should sign him, because they believed he was already the greatest featherweight in the world.

After McGregor racked up eight wins (all finishes) in less than two years, White finally came calling, signing McGregor and matching him up with Marcus Brimage on the UFC's April 2013 show in Stockholm.

McGregor knocked Brimage out in just over one minute.

A few months later, White brought McGregor to Las Vegas to spend a little time with him while also discussing a new contract. It was here that McGregor was truly introduced to the UFC's international fanbase.

He released a selfie video of himself riding in the passenger seat of White's Ferrari, screaming down the Las Vegas strip. Titled "the king's meeting in Las Vegas," the video encapsulates all that is McGregor.

"It's the king of Las Vegas, Dana White, with the King of Dublin, the Notorious Conor McGregor," he yells over the wind. White, driving the car, has the biggest smile on his face, as though he has realized he might've stumbled onto the next big thing. White guns the car, and McGregor laughs maniacally.

McGregor's star began to grow. He beat Max Holloway by decision, and then the UFC announced an event in Dublin. McGregor, in just his third UFC bout, headlined the card and knocked out Diego Brandao in the first round. Afterward, he cut a spirited promo in front of the Irish fans. That event is still considered by many to be one of the best in UFC history.

McGregor celebrated afterward with White and UFC executive Lorenzo Fertitta, drinking expensive Irish whiskey and making plans for the future.

And that future was bright. He knocked out Dustin Poirier in 1:46 last September and then did the same to Dennis Siver earlier this year. In less than two years, and in just five fights, McGregor had become one of the UFC's biggest stars.

The UFC intended to capitalize: It booked him against featherweight champion Jose Aldo in July and scheduled an unprecedented world tour that would take both men to all corners of the globe to hype the fight. The tour ended in Dublin, where McGregor held the fans in attendance in the palm of his hand.

At the end, he stood up from his seat on the stage, rushed to Aldo's side and grabbed the champion's belt. He held it up and screamed at Aldo, who lunged at the challenger, screaming while trying to get his belt back. White separated them with a grin on his face. Money was in the air, and promotion for the UFC's biggest fight of the year was well underway.

McGregor is painted by the UFC as a national Irish conquering hero who, when he steps in the Octagon, takes with him an entire country full of supporters. White once famously said that when McGregor fights, the entire country of Ireland shuts down.

The truth, as usual, is more nuanced.

He is known by nearly everyone in the country. Stop anyone on the street and mention his name, and it is almost certain their face will register a reaction of some sort. Bartenders, cab drivers, hotel bellhops—all of them know who he is. His appearances on network television and in Ireland's largest media outlets have ensured that he is a known commodity to all on this tiny island.

But there is a great divide among the Irish regarding McGregor and his rise to fame. Those who are young and perhaps already into mixed martial arts love him and everything he represents. To them, he is a hero, someone who escaped the dreary life of a plumber and made something of himself. And he is a fighter, which endears him even more to the Irish. Shout his name in a pub, and you are likely to be met with a chorus of fervent supporters.

But there is little love lost for McGregor among older Irish citizens. Many older than 35-40 years old generally don’t like the way he handles himself. They’d like him to be a little more humble. Irish sporting heroes have generally been quiet and unassuming; the boxer Katie Taylor is often referenced as one of Ireland’s greats and held up as an example of the ideals they would love all athletes to strive for.

At the massive Croke Park, the home of Gaelic football, hurling and perhaps a future location for a McGregor fight, 72-year-old Francis Curran—a diehard hurling fan who came to Croke to take the Etihad Skyline tour (a walkway on top of the roof of the stadium that must be experienced to be believed)—acknowledged that he knows who McGregor is; he just doesn’t appreciate the way he behaves.

"I hope he gets beaten. And not just beaten, but beaten badly, so he’s bloody," Curran said. "I’d like to see him lose, and then he can go back down and try to make his way back up with a little respect. It was the same thing with Muhammad Ali; we wanted anyone to come along and beat him."

This is a common refrain among the older Irish, most of whom do not watch the young-skewing UFC. Most are fans of hurling, gaelic football or football. If they watch combat sports, it is usually boxing. Tony, Conor's father, says this is not surprising, because mixed martial arts is still often misunderstood.

"The older generation, they just don’t get it. This is a brand-new sport. And it’s a brand-new sport to Ireland," Tony said. "And for Ireland to have this brand-new sport, and to have a hero that goes along with it? It’s incredible. So the old folks just don’t get that."

Ireland does not have many sporting heroes. It is a small nation with a rich and proud history, but it has not produced the same kind of laundry list of athletic greats as England and other countries in the region. And so those who make it—regardless of their chosen sport—are often instantly catapulted to fame.

"Even if you were playing tiddlywinks and you won the world championship, you would be instantly fated as a hero," Tony says.

Conor says he has never experienced any kind of hate in his home country, even from older citizens, and notes that the way he's portrayed on television does not wholly reveal who he is.

"I am not arrogant when anyone meets me. I am nice to people. I keep to myself, and as long as people are nice to me, I am nice to people," he says. "I’ve never encountered anything like that. Usually, if people have that opinion of me, they walk away from meeting me thinking differently.

"But I can’t control what people think of me. I live my own life the way I see fit. I cannot worry about the way people portray me, because people portray me in many different lights. This is the life I am in, so I can do nothing but accept it and carry on."

McGregor's bout against Aldo was derailed when, in late June, it was reported the champion had suffered a broken rib in training. After several days of uncertainty, the UFC issued a press release saying Aldo's ribs were only bruised, not broken, and that he was planning on defending his championship.

The Brazilian doctor who examined Aldo insisted that his ribs were broken, however, and on June 30, the champion withdrew from the bout.

Perennial top contender Chad Mendes had already been tabbed as a replacement for Aldo in case the fight fell through. The UFC announced that McGregor and Mendes would fight for the interim featherweight championship while Aldo healed.

McGregor focused on staying positive, despite the chaos. All of the things he'd learned from The Secret, and all of the ways he'd seen the law of attraction help him prosper, helped him get through a time when the biggest opportunity of his career faltered and then vanished.

"We’re all human at the end of the day. For me, it’s just when something happens, I take a step back and put myself in a positive frame of mind," he says. "If it’s something I can control, I will control it. And if it’s not, I let it be. I have things that motivate me. I think of where I am in this game and where I was before, and then I carry on. And that helped me through it."

And so McGregor will be at UFC 189, carrying the pride of his country on his back. Thousands of Irish fans have booked flights to Las Vegas; they will turn up in droves, taking over the casinos and the bars and the attractions. Many of them will be adorned with the Irish flag. If you are in Las Vegas this week, do not be confused: You have not been transported to Dublin; rather, Dublin has been transported to you.

McGregor has come a long way from Crumlin and Lucan, from the directionless boy to the focused man. His family—especially his mother—misses him greatly, but they realize he's on his own journey now and that he must see it through. They talk to him occasionally, texting messages here and there, but mostly they leave him to his mission.

And what is that mission?

To be the greatest fighter on the planet. To be the best fighter of all time. To leave a legacy in the fight game for Ireland, a fighting country constantly in search of heroes. To make as much money as possible. And to continue to grow the sport, both at home and abroad.

"That’s what I take great pride in. We are a fighting nation. So to be first on this stage, and leading the way? I have no doubt the next generation will come on and continue my legacy," he says. "We will continue to run the game long after I am retired.

"I am happy to play a great part in history. But long after I am done, my story will be told."

Jeremy Botter covers mixed martial arts for Bleacher Report. Follow him on Twitter.