It's not the most powerful animal that survives. It's the most efficient.

I will never take the fact that I am Welterweight Champion for granted. I learnt my mistake in the past. No matter how great, no matter how people tell me how great I am, I'm always one mistake away from losing everything.

A cockroach can’t defeat a dinosaur. But the cockroach is better at one thing, and it has ensured its survival through the ages: Adaptation. One could adapt to the environment and the other one couldn’t.

People have mistaken my break, I took a break from competition, it was because of mental problems, and because I was not agreeing with Performance Enhancing Drugs. I put the things on pause for a while, but I didn't retire.

For me there is no reason why to go up in weight class, because when you go up in weight class you have to fight bigger guys - then you have to train against bigger guys. The guys are not better, they're heavier, but it means you have more chance to get hurt.

It's not always the best team that wins the game it's the team that plays better.

I don't want to be an exception, because I was very outspoken about Performance Enhancing Drugs. It would be bad for my reputation if I would have an exemption [for doping test] - I don't want to have a free pass, I want to be like everybody else.