Knock, Knock!!

Last night I went to visit a friend who also lives in a high rise building. He lives on the 10th floor, but I accidently hit "8 "instead. I quickly hit "10" as well; however, I then got out on the eighth floor thinking it was the 10th. I knocked obnoxiously loud on "my friend's" door. A frightened old lady answered! I just stared and realized my own mistake. She must have thought I was a freak!