I'll drop something for a while, a year or maybe several years, and then pick it up again. I think that's the way successful innovators work. They keep juggling ideas, keeping them in the air, in the back of their mind, to inspire them or enable new recombinations.

Nothing succeeds like success. Get a little success, and then just get a little more.

Some people may have greatness thrust upon them. Very few have excellence thrust upon them. They achieve it. They do not achieve it unwittingly, by “doin' what comes naturally”; and they don't stumble into it in the course of amusing themselves. All excellence involves discipline and tenacity of purpose.

What could be better than walking down any street in any city and knowing you're the heavyweight champion of the world?

I can have three touchdowns and 200 yards, but if we lose the game, what's it all for?

One or two years ago, I didn't know who I was on court and I used to swear a lot. But now I've learned how to cope and can therefore win 10 matches in a row. I want to be remembered as a good player rather than an idiot on court.