Obsessive Compulsive Disorder (the mild kind)

I am slightly obsessive compulsive.  Not out of control, but just things like wanting things to be arranged a particular way, lining stuff up on my desk, and obsessing somewhat over things that are beyond my control, the latter of which is mostly seen in the perpetual replaying of possible scenarios regarding future and past events. 

So why am I posting this?  Funny story about how I finally figured out that I had a mild OCD.  Sitting in a college class and the girl next to me, who was in my study group, borrows my ruler and then sets it back down on my desk.  Does it again, and again, and again.  Pretty soon she starts giggling.  I have no idea why.  After class she asks if I have any idea why she was laughing so much. Turns out that she was setting the ruler down crooked, and I was straightening it.  Every single time.  Without ever noticing.  Awesome.