I had a friend who was pretty OCD. All his shirts were sorted in his closet by sleeve length, then sub-sorted by color in alphabetical order, etc... Same with pretty much everything in his apartment. Books on his shelf were better sorted than most libraries or bookstores. Over the course of a year, we would break into his apartment and make little changes; move some things around, mess with his clock, move his pillow, eat some of his food, move things around on the desktop of his computer. Just little tweaks. I thought the poor guy was going to have a nervous breakdown. He almost came to blows with his brother, who was his roommate. When he finally found out it was us he went ballistic and tried obsessively to prank us back to no avail. The final straw was when we filled all of the sinks and the tub in his apartment with playground sand. We covered all the drains with duct tape to not cause any damage but that was a nightmare for him to clean out. Good times.
