I am two different people. What you see on the court is just natural for me. I wear my heart on my sleeve. I have always said 'C'mon' purely to fire myself up. Off the court, I am a lot shyer. I stick to my team and my family and people I trust.

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.

I wanted to work towards the four majors and the Davis Cup. I know to a lot of people it may not mean too much, but to me (Davis Cup) means an awful lot.

I'd much rather win in three or four sets than go the distance all the time. I seem to put everyone through the wringer quite a bit.

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.

Grand Slams are different. If you can get through a few matches, the draw opens up and you get confident. You just need a little bit of luck early, you get through those opening matches and you never know what could happen.

That's what you do all the hard work for, to play in situations that put your body through gruelling times. If you're not up to it, pull out.