A sandwich walks into a bar.

This classic bar joke is a masterclass in misdirection (Review) and absurdity. The humor comes from the subversion of our expectations. By personifying an inanimate object, the setup leads us to anticipate a clever pun based on sandwich ingredients or types. We're ready for the bartender to ask, "What'll it be, hero?" or for the sandwich to say, "Just a club soda."

Instead, the punchline completely ignores the surreal event of a walking, talking sandwich. The bartender reacts not to the sentient customer, but to the literal object in front of him. This deadpan, logical response to a completely illogical situation creates a delightful anti-climax (Review). The joke isn't about the sandwich's witticism; it's about the bartender's hilariously mundane rule-following in the face of the bizarre. It's a perfect anti-joke, finding its comedy by refusing to play the game.