I have depersonalization disorder (
I blogged about it here, if you want more info). But my grandfather who raised me had OCD along with a host of other problems, most creepy of which is that he was totally a sociopath. He could magically turn off all his problems whenever he needed to look good or impress somebody. But when people weren't looking, he talked to himself in a creepy sounding high voice, he couldn't stand to have somebody walk on a path that he could potentially walk on along with a host of other weird ticks and rules that turned our house into circus sideshow.