It is easy to be independent when you've got money. But to be independent when you haven't got a thing, that's the Lord's test.
At 35, I'm definitely starting to feel more like a grown-up than I ever have. There's nothing in my life that is childish or whimsical. Having fun is fantastic and I never want to lose a sense of that - and also, I think, you have to have that to put into your work or else it's going to feel stiff.
As soon as I step on the court I just try to play tennis and don't find excuses. You know, I just lost because I lost, not because my arm was sore.