I have that problem all the time. I love to write, but it's figuring out what to write about that I have a problem with! I generally just ask everyone I know what to write about. I get a lot of interesting suggestions of topics. One usually sparks some thought. I don't neccecarily write about that topic though... it generally just gives me idea, and I form my own topics of that idea.

I don't really know what would spark your interest in writing, but I say you should write something about obsessions!?