I honestly think I am a better player than I was four years ago, when I was No. 1 in the world.
I was worried a bit at the beginning because I didn't know how the situation was. Once the ATP wanted to do the tournament, I realised there was no risk at all. I'm very sorry about what happened. It's not easy to be here knowing so many people were killed very near from here.
It's not easy to play your best for 40 weeks. It happens every year, I don't play well in Rome or Hamburg -- I don't know why -- but then I play well after that.