In my mind, I'm always the best. If I walk out on the court (and) I think the next person is better, I've already lost.

The most fun part about working out is being done - getting through the workout, let's be honest. But that feeling afterward? Yeah, that's worth it.

To be a well-rounded person and know what's going on in the world around you, to have a perspective outside of your sport, is important for every athlete. I'm blessed that our parents gave us that.

I don't carry a purse when I fly because I have my Hello Kitty carry-on. I'm the biggest adult supporter.

When you lose, you're more motivated. When you win, you fail to see your mistakes and probably no one can tell you anything.

To stay interested in tennis, I have to mix it up with other things.

Every Olympics is something special. If you're fortunate enough to play for your country - there's just so much energy. It's truly amazing.