After a visit from footballer Cristiano Ronaldo in the gym this week, Conor McGregor promised to challenge the world's highest paid sportsman for number one position on the Forbes rich list next year.
With his once-in-a-lifetime personality and exciting fighting style, the Irishman has become the biggest star in mixed martial arts. But it wasn't always that way.
Like the words of the rap artist who McGregor shares a nickname with, Notorious B.I.G., this is a real life rags-to-riches tale.
We used to fuss when the landlord dissed us
No heat, wonder why Christmas missed us
Birthdays was the worst days
Now we sip champagne when we thirst-ay
Uh, damn right I like the life I live
'Cause I went from negative to positive
And it's all good
McGregor's financial troubles as a youth in Ireland were revealed in his long-time coach John Kavanagh's recently released autobiography Win or Learn.
Before becoming the UFC's biggest earner he relied on his girlfriend, Dee Devlin, to ferry him around in her old Peugeot - which needed to be push-started.
Kavanagh recalled narrowly avoiding missing a flight to Sweden for McGregor's first fight in the UFC because his charge insisted on stopping to pick up his 188 euro-per-week unemployment cheque on the way to the airport.
"For weeks leading up to the fight, he had been all over Irish TV, radio, websites and newspapers, as they reported on the much-hyped young Dubliner who was aiming to become the first Irishman to win in the UFC," Kavanagh wrote.
"Yet here he was, queuing up in his local post office en route to his UFC debut, waiting to collect the 188 euros that he couldn't afford to be without."
McGregor's life would change forever a few nights later in Stockholm as he unloaded a series of uppercuts to the chin of Marcus Brimage to win via TKO in 67 seconds. A star was born.
"Given the manner in which he put Brimage away, I was confident that Conor would be in with a good shout of being awarded the 'Knockout of the Night' bonus worth $60,000 - a significant financial boost considering that his pay for the fight was $16,000," Kavanagh wrote.
"As the (post-fight) interview (in the Octagon) was drawing to a close, I mouthed to Conor: 'Ask for the money.' UFC president Dana White was in attendance, and I thought he might be persuaded by a cheeky young Irish newcomer asking for the bonus. Conor grabbed the microphone and shouted: 'Dana, 60 g's baby!' ...
"On the way to the fight in Sweden, Conor had collected the dole. On the flight home, there was a cheque for $76,000 in his pocket. I sat back, closed my eyes and smiled. Now the public had been introduced to Conor McGregor, things were never going to be the same again."
'I TOOK CONOR DOWN AND BEAT HIM UP'
McGregor first walked into Kavanagh's gym in Rathcoole, Dublin, in late 2006. Kavanagh - who was Ireland's first ever black belt in Brazilian Jiu Jitsu - had turned his hand to coaching after deciding life as a bouncer or an engineer (he had a degree) wasn't for him.
Despite having trained only as a boxer to that point, McGregor referred to himself as a future UFC champion in his first exchange with his new coach.
The eager 18-year-old was keen to make an immediate impression and dropped one of the gym's top fighters, Owen Roddy, with a body shot during his first sparring session.
Kavanagh didn't approve of fighters in his gym training like that but decided to overlook it and went to his office. He wasn't there long as McGregor went a step too far.
"What happened next was definitely unacceptable," Kavanagh wrote. "I was sitting in my office when I heard someone outside say, 'That fella is after dropping Ais'. I knew straight away it was Conor, because (female fighter) Aisling Daly had stepped in with him after Owen. I came out of the office and saw Ais keeled over in the ring. She was in tears. Conor had hurt her with a body-shot.
"Okay, I thought, I let you away with that once, but you've got another thing coming if you think you can come in here and bully people. 'Right, Conor, I'm next,' I said. After strapping on a pair of gloves and stepping into the ring, I took Conor down and beat him up until he received the message loud and clear: These people are your teammates, not your opponents.
"When we finished, Conor looked at me and said: 'Yeah, I deserved that'."
'YOU'RE RIGHT, LET'S DO IT'
McGregor almost never made it to the UFC. After winning the first two fights of his professional career by knockout he was submitted via kneebar by a Lithuanian fighter on a card in Dublin in June, 2008.
But that wasn't his only problem on the night. Kavanagh had given him 25 tickets to the show to sell for 20 euros each, but when it came to hand in the 500 euros worth of sales, McGregor didn't have it. Perhaps ashamed of what he'd done, McGregor didn't come to the gym for two months.
Soon after McGregor's mother, Margaret, called Kavanagh pleading with him to come and speak to her son. He was in a state of depression, refusing to leave his bedroom for most of the day and had begun hanging around with the wrong crowd.
"In spite of the incident with the tickets, I liked Conor and knew he had the ability to go places in MMA," Kavanagh wrote. "His family had gone to great lengths to have me come over and speak to him. I was willing to give Conor a clean slate, but from Monday onwards it was never to get to this stage again.
"'Whatever you need, I'll provide,' I said. 'But you don't take a step back or fall off this path. You've got to give me everything back, 100 per cent'. Conor took it all on board, looked me in the eye and said: 'You're right, let's do it.'"
The rest is history.