I knew I was the second-best tennis player in the state of Florida and No. 8 in the United States of America when I was 12 years old and I couldn't tell you what I was in baseball, but I liked my chances in tennis of getting a scholarship to college.

What separates the winners from the losers is that they can deal with doing their best while still coming up short.

You have to be extreme to be exceptional. I couldn't revel in being number one. I had to get to zero. When my fitness was at its peak, I was intimidating. I made guys cave in. They'd be dejected in the locker room after matches, and I'd go out for a run, as if it wasn't enough. I'd rub it in their faces. I meant to do that.

Even the poor can be fat in the U.S. That says something about a country. That's how incredible what we have is. But it can also take away incentive.

The airplane has had a big impact on my life.

There's a reason why Federer and Nadal are so gracious when they lose. They sleep well at night knowing that they've given their best.

If you don't want to practice, unless you have a hard-nosed coach, you don't have to.