Maria Sharapova: The granny of tennis, age 24
"I love competing and there's nothing else in my life that gives me that, whether it's designing or doing a photo shoot. Many things in life are controlled by other people, especially in their work. In my work, in my career, everything is controlled in my hands.
"That gives me such a freedom in a way, because I know that if I lose a match it was in my hands. I could have won it, but I lost it. There are people around you in the team who help you and prepare you and get you ready, but at the end of the day it's about you, and it's you trying to beat your opponent. That's the best feeling."