I don't know. Haven't I always been mature?

I'm more in that Rafa Nadal high-energy high-octane mold out there. I wear that emotion on the court. That's how I play my best tennis. People either like that or not. And I can't change that: that's who I am on a tennis court.

When I go out to play, I still believe I'm as good as anyone out there. I don't have to prove anyone wrong. I know what I've done and how well I can 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.

Maybe I have to work a bit harder on clay. It's a challenge and I've always liked challenges. Whether I will ever win the French and master playing on clay, who knows? But I'll give it a shot.

Maybe if you're playing in London or America, you don't feel that pressure quite as much.

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.