There's certain things that you cannot cross, no matter who you are, what you're doing or where you're coming from.

I would say that Roger Federer is pretty amazing. And Manny Pacquiao - he's such a tiny, little lightweight guy, but the way he fights makes people so excited.

I learned in my Ph.D. the discipline I needed to be successful. Most boxers are not that disciplined. They have talent, but the self-organization - the ability to schedule yourself and your priorities - is lacking. My studies were about the control of training on both the psychological and the physical side.

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.

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

I've been many times to Dubai and the U.A.E., and I have friends that live there. It would be exciting to stage world heavyweight championship fights in the Arab world. It's something Muhammad Ali achieved when he fought in Zaire or the Philippines. It's absolutely exciting to fight in countries where you have never fought.

Mental strength is really important because you either win or lose in your mind.