I had it in my mind: to be confident, and to keep saying that until the confidence appeared. But I took it too far. Confidence did help make me champion, but, man, I took it to a whole different level. I was a megalomaniac. I was not humble and it eventually came back on me. So I want my kids to know, keep humbleness and kindness in their hearts. It will prevail.

I earned that the strong will always beat the weak, but the smart will beat the strong. Boxing is a tough guy sport. But in the end, the tough guy gets to clean the streets and be a bodyguard. In the ring, the tough guy is going to get hurt; at the end of the day, he's going to talk funny. Only the smartest win. So, I know it's cliché, but power - real power - comes from knowledge, comes from smarts.

I could feel his muscle tissues collapse under my force. It's ludicrous these mortals even attempt to enter my realm.

I didn't know how to be any other way. I felt like one of those barbarian kings just coming to conquer the Roman Empire.

You should sit in meditation for 20 minutes a day, unless you're too busy, then you should sit for an hour. If Tetris has taught me anything, it's that errors pile up & accomplishments disappear. Everybody has a plan until they get punched in the mouth.

I've been a prima-dona. I was taken care of since I was 13. That's why I am the way I am today. I was spoiled, like a brat. I had anything I wanted. That's crazy to be that way all your life. Everybody's taking care of you, but manipulating you at the same time. Very few people have a life like that. Most people have to work like slaves their whole lives. I've never had a job in my life. What I know how to do is hurt big, tough men - in the street and off.

When you see me smash somebody's skull, you enjoy it.