Also, if someone 15 floors below or above you is using a jackhammer, your day is screwed. Or, if there's a child who is bouncing a ball against the wall in some appartment. The noises travel pretty well across the structure, that's why I prefer to live in a building which has as few units within a single structure as possible. Mine curently has 25, which is livable, previous one was over a hundred and was much worse in this regard.