I often surprise myself. You can't plan some shots that go in, not unless you're on marijuana, and the only grass I'm partial to is Wimbledon's.

I often surprise myself. You can't plan some shots that go in, not unless you're on marijuana, and the only grass I'm partial to is Wimbledon's.

Staying interested in a match is a lot harder than many people think. Throughout my career, I've always had trouble in the early rounds of a tournament mainly because it was hard for me to psychologically get up until I got to the quarters or the semis. What happened a lot of times is that I would fall behind early, maybe even lose the first couple of sets in a five-set match and then begin to concentrate. Still it wasn't something I could control from the start.

When you have the opportunity, you strike.

The roughest thing I ever said to an umpire was, 'Are you sure?'

The time your game is most vulnerable is when you're ahead; never let up.

Roger Federer certainly is my claim to be the best of all time - if there is such a thing. With Rafael Nadal not far behind.