What OCD do you have?

Today we had an interesting chat about OCD's. This is because there is a man who parks his car at the same train station as me every morning who has got an OCD. He gets out of his car, locks it, then checks every door is locked. He then goes to wait on the platform thinks his car is unlocked so he goes back to his car to check all the doors again. He does this 3 to 4 times everyday. I have even saw him check his bonnet and boot are locked as well. It must be a pain in the arse for him but I can't help but laugh. I wonder what time he has to leave his house in the morning?, 3am? just make make sure his front door is locked before he finally drives to the station.

I have a couple of OCD's:
One is I have to line up all my DVDs perfectly on top of each other otherwise it really bugs me (pic).
The other is I have to put my left sock on before my right sock and my left shoe before my right shoe. This because when I broke my ankle 12 years ago playing football and I remember putting my right boot on first. I think this OCD developed from being a superstition into an OCD.

I wonder what weird and wonderfull OCD's everybody else has?