I understand that the results I've had in my career, or I'm having now, they are very good. And that gives me confidence, of course, but I do not feel invincible.

I lost to a better player who played some courageous tennis and deserved to win.

What I learned as a young child continues to have a tremendous impact on my life today.

You have to consistently be successful to be one of the top players in the world, and everything is possible in life.

I embraced, I think, the process of becoming No. 1 of the world, which was long and difficult, but it's sweeter in the end.

Tennis players we're always playing in center courts that feel like arenas. And when we get on the court and the crowd cheers your name or salutes you - it's like you're a gladiator in the arena. And everyone is cheering - and you're fighting, you're screaming, during your strokes - it feels like you're an animal, fighting for your life.

Each year represents new challenges and obstacles. You have to adjust.