A great source of calamity lies in regret and anticipation therefore a person is wise who thinks of the present alone, regardless of the past or future.

I was an OK boxer, I wasn't great, I was OK, but I loved the discipline of getting together every Monday, Wednesday and Friday, usually Saturday afternoons too, with a whole bunch of mates and training, very, very hard for about two-and-half hours.

All of the great leaders have had one characteristic in common: it was the willingness to confront unequivocally the major anxiety of their people in their time. This, and not much else, is the essence of leadership.

I went through life like an idiot for a great deal of the time, saying there's nothing I would change. That was a very arrogant thing to say. There's a lot I would change. There are people I would have steered clear of.

A great tennis career is something that a 15-year-old normally doesn't have. I hope my example helps other teens believe they can accomplish things they never thought possible.