In my case, I can sincerely say nothing is impossible.

Mostly the problems when I was down were caused by myself. There were times when I was not responsible enough or decisive enough.

In order to stay where I am - and I want to do that - I have to stay dedicated as well as I have been before I became No. 1.

I'm trying not to pay too much attention to the rankings because calculations can distract you.

Tennis is my life, obviously; I need to focus, I need to win. But it's not the only thing. I'm not going to play forever.

I cannot guarantee anything.

I always try to have something that keeps my mind relaxed, keeps my mind a little bit off tennis.