Guilty of that toobarres wrote:My habit of locking the doors is so ingrained that I have been know to lock the back door after sticking my head out to check on my son while he is playing. He then gets rather annoyed that he is locked out of the house.
But if you really want to annoy someone, try locking your wife out 
When close a door, I lock it. I've finally gotten my wife and son to do a better job of this too. Took much fussin though.