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.

If you're a champion, you have to have it in your heart. You can have the greatest coaches in the world, all the opportunities to play, and the greatest equipment, but if you don't have it inside, you're not going to make it. On the other hand, if you don't have any of those luxuries but you have heart and courage and the guts to go out there and grind it out, then you'll make it.

The difference is almost all mental. The top players just hate to lose. I think that's the difference. A champion hates to lose even more than she loves to win.

Don’t let a first-set victory lead into a second-set slump

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.

The great high of winning Wimbledon lasts for about a week. You go down in the record book, but you don't have anything tangible to hold on to. But having a baby -- there isn't any comparison.

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.