Now that I'm losing some, I can see how tough I was -- the killer instinct, the single-mindedness, playing like a machine. Boy, that's what made me a champion.

Ninety percent of my game is mental. It's my concentration that has gotten me this far. I won't even call a friend on the day of a match. I'm scared of disrupting my concentration. I don't allow any competition with tennis.

Now that I'm losing some, I can see how tough I was -- the killer instinct, the single-mindedness, playing like a machine. Boy, that's what made me a champion.

In tennis, at the end of the day you're a winner or a loser. You know exactly where you stand... I don't need that anymore. I don't need my happiness, my well-being, to be based on winning and losing.

Losses are always a relief. They take a burden off me, make me feel more normal. If I win several tournaments in a row I get so confident I'm in a cloud. If I lose I go back to the dressing room and I'm no better nor worse than anyone else. A loss gets me eager again.

Training the body to obey the mind as I have done differs from the more conventional method of getting the mind to obey the body.

I always looked ahead.