You know you've been wondering.
At work I have a preferred stall. Do other people do this? I try not to use handicapped stalls because I feel guilty. So that leaves 2 regular stalls. I try to use the one in the middle because I have the (probably incorrect) idea that the one next to the wall is smaller.
At home I close the door even if no one's home. Partly out of habit and partly because if I don't my dogs will stand in the doorway and stare at me which creeps me out. On the other hand the cat follows me in to the bathroom all the time and this doesn't bother me at all. I'm not sure what this says about me.