Are there any little things that you simply must do? Sort of like an OCD tendency?

Sometimes I have to check and double check if my front door or car doors are locked, especially if I am going out for the day. I'd love to know how my brain works on this. "Well, I know I locked it 2 seconds ago, but what if it somehow became unlocked in that time? Better lock it again just to be sure!"

I am also really bad with cracking my knuckles. I can do each finger in two different ways and then I have to wait a little while for them to "reset". Once I get the idea in my head to do so, I smurfing have to do each and every one. It feels so awful not to. Normally I just go ahead and do so, but it's a bit more difficult if I am driving or playing a game!

So that's my craziness documented (as if every post I make at this website isn't somehow a manifesto of lunacy) but what about yours?