I had so many outs in my career. I could have said, I don’t need this. I have money; I have fame; I have victories; I have Grand Slams. But when your love for something is bigger than all those things, you continue to keep getting up in the morning when it’s freezing outside, when you know that it can be the most difficult day, when nothing is working, when you feel like the belief sometimes isn’t there from the outside world, and you seem so small. But you can achieve great things when you don’t listen to all those things.

You have your bad moments in your career and your good moments. And it's been a good ride so far, but it's not over yet.

I'm never standing still and that makes my life pretty exciting.

When I need to push myself, I think of all those nicely polished trophies waiting to be lifted up by the winner - and how that winner might be me.

I'd probably start charging for medical timeouts. I think we'd all see who really uses them and who doesn't.

I still love things that you don't even need to pay for. Going to the beach and being around five of your friends and having a good time means so much more than going out and spending hundreds of dollars.

People always ask about young people like me being forced into things. I play tennis because I love it. I think Russians might be tougher than other people. When I arrived in America I was young, but I already knew what I wanted. I think that when you start from nothing, when you come from nothing, it makes you hungry. I am proud of where I came from and I know what I want. I want to win.