I almost locked myself in an abandoned jail cell back in the 90s. I was exploring an abandoned military stockade after the base closures. The jail cells were open. I walked in one and thought “I should close the door to see how it feels to be in here with the door closed.” I started closing it, then just before it finished closing I thought “check to make sure it doesn’t lock.” So I stepped out, finished closing it, and it locked. I was shocked. I almost dismissed the notion that it would lock because I figured that there is no chance they would abandon a stockade and leave the door locks functional, and still set so they automatically locked if anyone closed the door. If I had shut that door while in the cell, I would have had no food or water and no way to get out.