Ninety percent of my game is mental. It's my concentration that has gotten me this far.

If you can react the same way to winning and losing, that's a big accomplishment. That quality is important because it stays with you the rest of your life, and there's going to be a life after tennis that's a lot longer than your tennis life.

I can definitely say the same thing [discussing Steffi Graf's claim that she had played against at least one top player who used steroids]. Steroids can really make a difference, physically and mentally. I'd be really disappointed if I had been ranked No. 2 behind someone who took steroids.

My first U.S. Open I think was just very special for me because that was sort of the beginning of what was a 'Cinderella' story for me.

I've had a lot of fear in my life, from fear of flying to fear of making a speech in front of a lot of people.

Competitive toughness is an acquired skill and not an inherited gift.

I realized that with hard work, the world was your oyster. You could do anything you wanted to do.