Habit

 I have a strange habit I never knew I had. After my walk, I lock the door when I come in house. I don't even notice doing it. I don't think we even need to lock the door here in the 'hood. Tonight Barb came home from pickleball in the evening and was locked out of the house. She had to ring the doorbell. I let her in. She was mad and asked why did you lock the door. I said I didn't lock the door. It must have locked itself. Of course, a bolt lock can't do that.