When I was a kid in Adelaide, I dreamed of becoming No. 1 in the world, winning a grand slam and the Davis Cup for Australia.

I'm fortunate: I can play as long as I want to play. There's no coach or trainer who is going to say to me that I'm dropped or sacked, it's time to move on. I can play as long as I want to play.

(Andy Roddick's) a different kind of guy. I don't spend a lot of time with him. His coach in the past (Tarik Benhabiles), I didn't have a lot of time for at all. He was a bigger problem than Andy.

I've probably put up with more criticism than a lot of people out there. At the end of the day, you block out everything, especially with your personal life.

I'm one injury away from hanging up the racket at any time.

That's when you've got to grit your teeth and hang in there and try and find a way to win when you're not playing your best tennis - that's what I can be proud of

I was lucky enough to win the Davis Cup in my first year in 1999. I won my first slam at the U.S. Open in 2001 and became world No. 1 later that year. By the age of 20, I'd done it all.