Trying to win tournaments I've never won before is a huge motivation, but I'm not trying to compete with Stan Wawrinka in terms of the numbers.
I know Stan - who I face in the semi-final on Friday - and we have both won three Grand Slams but I don't compare myself with other players in that sense. It's not what I'm playing for.
Over the last few years Stan has played great in the Slams, he's been very consistent.
In the US Open final last year he definitely deserved to win. I also think when he played the French Open final here with Novak Djokovic, he played extremely well.
He deserves the titles that he's got but his success doesn't affect how I feel about mine.
Whether it's Roger Federer, Rafael Nadal, Novak or Stan, I don't need to think about the amount of Slams they have for any motivation.
BBC Sports