Obviously, I'm good with mechanics.
There was an old man who used to throw rocks at me when I rode to school. (I named my resident ghost after him) One night, in the middle of the night, I sneaked out with a machine I built that, if someone puts mail in his mailbox, it feeds it into a belt loop and, when opened again, shoots the mail back at the recipient. He still threw rocks at me, so I started putting rocks in the belt feed. He STILL threw rocks at me. He never stopped until the day he died, and I never found out why he hated me so much...