I had a roommate in college and I just hated her so much. One time when she was sleeping I ran over to her bed, punched her in the head, and then jumped back in my bed before she could see that I was up. The next day I told her she had been hitting herself in her sleep, and I managed to convince her that she dreamed I had punched her in the head. It worked so well I did it three more times while we lived together. She fell for it every time.
Confession posted on 12/26/2000