“Fear is the greatest obstacle to learning,” "Iron Mike" famously once said. “But fear is your best friend.

“Fear is like fire; if you learn to control it, you let it work for you. If you don’t learn to control it, it’ll destroy everything around you.

“Like a snowball on a hill, you can pick it up and throw it before it starts rolling down, but once it rolls down and gets so big, it’ll crush you to death.”

Although Dubois does not choose to articulate his own feelings with quite the same eloquence, the sentiment of Tyson’s quote definitely rings true for him. “For sure,” he nods when asked if agrees with former heavyweight champion's evaluation.

“I feel nervous every day. I'm a nervous character, that’s all I can say. I'm chaos so I'm just holding that chaos in until the fight. I know I'm chaos, I just need to let it go on the night. I'm just a chaotic character. It's just how I am.”

The WBO heavyweight champion is preparing for the first defense of his title against Fabio Wardley, the man he beat for it in Manchester five months ago.

That night, Dubois was dropped twice inside the first three rounds before he regained a foothold in the fight. He then began to apply so much of his own pressure that a bloody and battered Wardley was eventually stopped in the 11th.

The Ring’s No. 1 heavyweight admitted that pre-fight nerves had caused such a slow start against Wardley, but he disagrees that they will now simply be gone in the rematch at O2 Arena on Saturday.

“I'm just a fighting man and you go through how you are as a fighting person,” he says. “It's just about balancing it. It's a power for you if you know how to use it. It's about harnessing it.”

So what is it that makes him nervous? “I can’t say, mate. It could be anything,” he replies.

Okay. But do the nerves at least evaporate when the first bell goes? “No,” he says, smiling. “They get worse!”

Even so, Dubois (23-3, 22 KOs), a two-time world heavyweight champion at the age of 29, has managed to control his emotions for the most part throughout his career to date.

“I enjoy inflicting pain and putting that chaos on to the other guy,” he says. “What's inside me – the pain – I put on him. That's what boxing is, it unleashes whatever you have inside you. It's an outlet isn’t it? I’m just looking forward to it.”

Dubois is an intensely private person and little is known about his life away from boxing. How, then, does he control the chaos that defines him?

“I don’t,” he replies. “I even wreak havoc at home.

“Look, I’m not going to tell you about my life. Today is not the day but you might read about it in the paper one day.”