Can you say OCD? I had a guy living down the street from me. He would come out and lock his front door, then turn the knob and stare at it for a few seconds, then grab the doorknob and try to open the door to make sure it was locked. He would get in his car in the driveway and then get out and go check the door again. He would do this 4 or 5 times before he left and then he would leave and drive around the block and come back and jump out of his car and run up to the door to check it again. Finally he would leave.