When I was playing, we didn't have to compete against everybody in the world. Now it's a truly global sport, so the competition's much greater, just like it is for our children in every other area, whether it be in science or technology or whatever you talk about.

People say, "Do you know how much a million dollars is?" I don't have a clue. How many Big Macs will it buy me?

No one changes the world who isn't obsessed.

Bobby Riggs was one of my heroes. I admired him. That's one of the reasons I beat him - because I respected him.

Tennis is a game of angles. You never have time to figure the angles. It's practiced. It's so practiced that it becomes an instinct. You just know where to put the ball. You just feel it. It has been computed into your brain so many times ­ it is there.

I would just never out anybody. I think everyone has to find it in their own way and their own time.

If your partner wants to be private, you have to respect that.