I am bipolar and I am soooooo obsessive about anything and everything!!! At first doctors thought I had obsessive compulsive disorder, but I've recently been diagnosed bipolar and a trait of that is obsessiveness!!!
The main thing I obsess over is my appearance - I'm not a vain person, I feel very ugly, and I'm constantly checking mirrors to make sure I'm acceptable. I also obsess over guys and always have done, not as far as being a stalker. but I'll think about the person I have a crush on constantly, over analyse everything they say to me, and obsess over whether they like me or not!!!!