I should say that mental strength is No. 1, experience [is] No. 2, physical strength is No. 3, and genetic ability that you're getting from Mother Nature probably comes after.

Sometimes it's boring because it takes time, but it's enjoyable. So beating up people for a living is really fun.

I don't care where people come from. It is not important to me. If you are good people will like you, if you're not, they won't. It is simple.

It's not my place to compare myself to greats like Tyson, Frazier or men like that. But I would look at a fighter like Evander Holyfield. He's a great heavyweight who worked his way up through the weight classes to become champion and had to beat bigger men along the way.

I think that there's only one nationality and one language in the sport, and you call it performance.

I think a fight with David Haye, even if he is not American, is going to give positive vibes about the heavyweight division for the American fans and fans worldwide.

You can take your fitness seriously, but not yourself. That's the most difficult part: not to relax. That's the most difficult challenge I'm facing every fight.