I had a buddy in Columbus that put everything down the disposal. I advised him that he out to just throw it in the trash instead, and he scoffed. A week later his sink was backed up with sludge, and he had to get it snaked.
I also had a roommate once that refused to shave over a trash can instead of a sink, so it was always getting clogged. Generally these things are easily avoidable by minimizing the crap that you put down the drain.