I was watching Rainman this weekend and found the scene in the Doctor's waiting room pretty funny. While Tom Cruise if filling out paperwork for his autistic brother, there is an old guy sitting there 'expounding' on his knowledge about the pony express.
My favorite line was:"I might not have the names right or the dates right, but I know a little something about the history of the United States."
Sounds like a disclaimer that should be at the bottom of student's midterms.