Why we like locks

At 5am I was woken by what I thought was my cat playing with my keys. This idea quickly adjusted itself when I realized someone was trying to get into my apartment. I knew right away what was going on. The guy was drunk and at the wrong apartment. He was not shouting or carrying on but neither was he trying to be stealthy as in the manner of persons-who-are-up-to-no-good. Everything was locked so I was not worried, he was just keeping me up. So I turned on my computer and talked to a friend till he left/fell asleep (I suspect the latter), about an hour later. I woke up again at 7:40 and when I left for school he was gone. If he had been sleeping there I'd have taken his picture.