I was walking past the mental hospital the other day, and all the patients were shouting, "13...13...13." The fence was too high to see over, so I looked through a gap to see what was going on. Some idiot poked me in the eye with a stick, and they all started shouting "14...14...14." That's how I learnt to mind my own business!

This is a modern, anonymous joke that circulates widely in oral telling and on the internet (email forwards, joke sites, and social media). It belongs to a family of “counting inmates” or “asylum fence” gags in which a passerby’s curiosity leads to a prank and a punchline about learning a lesson. The setup relies on a stereotyped, comic depiction of a mental institution—common in older joke traditions—rather than any identifiable historical incident or attributable speaker. Because it is transmitted informally and appears in many slightly different tellings, it is typically cataloged as anonymous folklore/humor rather than a quotable line from a fixed literary source.

The joke dramatizes the proverb “mind your own business” by turning curiosity into immediate, physical consequence. The chanting of “13” creates a small mystery that tempts the narrator to pry; the eye-poke reveals the chant is a running tally of victims who look through the gap. Humor comes from misdirection (the audience expects an explanation for “13,” not that the narrator will become “14”) and from the narrator’s self-deprecating admission of foolishness. Beyond the punchline, it functions as a cautionary fable: some boundaries exist for a reason, and intrusive curiosity can make one complicit in the very spectacle one is trying to observe.