I have OCD, inherited it from my Mother. She was the worst I have ever known, but I try to keep mine under control. If I let myself go, everything would have a certain place and it would have to be there, everything would be spotless and organized down to a fine science. I could also be somewhat of a hoarder if I allowed myself to be. But I struggle every day with not letting it get that out of hand.
I do count things in my head obsessively, but that is just inside my own head, so it doesn't interfere with daily stuff. I do have a thing about even numbers, I really hate things to be left in an odd number if I can do anything about it.
I have a somewhat messy hubby, so I have to keep things under control or it would cause a lot of problems between us.