It should not be a child's only goal to become the best player in the world. That would be a bad, a harmful attitude.

You just try to play tough and focus point for point. Sounds so boring, but it's the right thing to do out there.

I was passionate about soccer. I still am. Odd, though - playing soccer always made me much more anxious than playing tennis. On soccer days, I'd be out of bed by 6 in the morning, all nervous. But I was always calm when it was time for a tennis match. I still don't know why.

It's more a tennis problem than a mental problem. The transition is difficult. It depends how much time you have. Playing on grass can sometimes be a bit of a lottery.

I do notice that I am tired.

I am happy with being a tennis player and the choice I took when I was 12. But clearly, if I wouldnt have been a tennis player, I would have loved to be a soccer player. But again, I am happy with the choice I made.

Stay healthy, do sports and above all have fun while doing sport. Competing or just for fun, whatever, simply enjoy and try your best. Working hard, working well with achievable goals normally pays off. Believe in the people that are with you and listen to those who have more experience.