It's always difficult, especially the U.S. Open, the last of the Grand Slams. It's always tough because you know, the season is very long. I really played a lot this year. Sometimes it's really hard to stay focused all the time because you're really tired after the whole season.
This is a dream from when I was kid. I'm playing tennis almost 18 years, and of course everybody's dream is to play the final of a Grand Slam.