I do what Mike mentions a lot and people make fun of it – but I'm a graphic designer so to me its just an expression… and I think you need a degree of OCD to be any good in the first place.
However, I do things like lock the car twice and then get half way out the car park and have to run back… it's something I'm keeping an eye on but not worrying about. I'm a very stressy person (not a psycho, more of a worrier/concerned) and a bit of a daydreamer so I think it's more a genuine case of locking the car without realising I'm doing it and then needing to check.
Either that or I'm flippin mental!