I'm definitely open to change, but at the same time I am quite stubborn.
My dinner options are kept simple during Wimbledon. I have either salmon with rice, roast chicken with vegetables and potatoes, or steak with salad. My girlfriend Kim will cook, and I know each night that it will be one of those three.
Obviously you try to keep as much of your private life as private as you can.
I used to think that losing made you more hungry and determined but after my success at the Olympics and the U.S. Open I realise that winning is the biggest motivation.
I had great success with Ivan Lendl. Was he a perfect coach? No. Was he a very good coach? Yeah. He had some very strong qualities and some things that weren't so good.
I've been asked a lot lately if tennis is clean or not. I don't know any more how you judge whether a sport is clean. If one in 100 players is doping, in my eyes that isn't a clean sport.
Boxers risk a lot in the ring. That's one of the things that attracts me to it. You want to see a knockout but I also really don't want to see people get hurt. It's this constant dilemma when I'm watching boxing. The only times I get nervous is watching a really big fight or when my brother is playing. I get to the stage where I'm actually shaking.
Earlier in my career, I used to spend a lot of time practising my tennis on court. Now I've learned that it's better to do just a couple of hours on court and two gym sessions a day. That's what's made me fitter and stronger.
A lot of athletes use sports psychologists.