This reminds me of an anecdote (from Edinburgh or Glasgow, I think) about a notorious troublemaker who once got carted off the mental hospital by the police. After a while the hospital released him with a document saying they couldn't find any sign of mental illness. He went on being an awkward old bugger for the rest of his life, but now he could back it up by saying that he was the only man in the city with a certificate to prove his sanity.