Mike Tyson understands the fight game as well as anyone.
So he's well-placed to break down exactly what has driven Conor McGregor's unprecedented rise to the top of the UFC universe - and why he's different to other popular champions like Ronda Rousey and Jon Jones.
"Conor is very charismatic," Tyson told fightersonlymag.com. "Jon Jones is bad, but deep down he's a decent kind of person and very shy.
"Whereas this guy, Conor, he's the man. He reminds me of the old-time boxers, one of those guys that's just into everything. He walks into the room and everybody stands up. He sucks the air out of the room. He's just a really interesting guy.
"He does things nobody else has been able to do too. He's kind of like an animated character, one that's real though. He's a great fighter, but his personality is even bigger than his talent. Isn't that crazy? He's got this huge personality. Nobody in MMA has ever had a personality as big as his.
"Ronda (Rousey) is just like a monster - the things she would do - but this guy is different. His personality is phenomenal."
McGregor and Rousey combined to help the UFC bounce back from one of its worst years in 2014 in a banner 2015.
The Irishman has made sure this year is off to a reasonable start too. The company doesn't release official pay-per-view numbers but UFC boss Dana White said McGregor's fight against Nate Diaz at UFC 196 generated more revenue than any event in its history.
While the estimated 1.5 million pay-per-view buys may have ranked second behind UFC 100, the higher price of the PPV combined with an $8.1 million live gate pushed the card into record territory.
That all means more cash in McGregor's pocket but despite plenty of evidence to the contrary on the featherweight champion's social media accounts, Tyson doesn't believe he's driven by the dollar.
"It's actually not even about the money, it's the power," Tyson said. "That's what it's all about. We never say it, but that's what he wants: power.
"That's why we put out lives on the brink of destruction, because we want to grasp that power. Nothing else matters. We almost want to give our lives up in pursuit of it. It's worth dying and killing for."