I retired because I had a knee injury, my cartilage was wearing out, it was painful and I couldn't put in the four hours of practice each day that I needed to.

Anything is possible as long as you have the passion.

It's a tough world out there and all the guys are fighting hard and the competition is really tough.

When we want to reach a dream for the second time, you want it to come true, when you try so hard, you are so close to achieving it, it makes things very difficult to live with afterwards.

If you lived the doubles, as I did, which was very stressful, you are sitting down in a chair experiencing a match without being able to hold a racquet in your hands.

More than specific memories of achievements, for me I remember the feeling you get when you were just at your very best - when you felt like you were floating across the court and could put the ball wherever you wanted.

But I still serve pretty big and that's one of my biggest weapons, so if my shoulder holds up and I can count on it, I can win a few matches and then you never know how the other guys are going to react to the fatigue and the length of the matches.