A sphere walks into a bar and orders a drink. The bartender says, "I'm sorry, but we don't serve spheres here." The disgruntled sphere walks outside, but then gets an idea and performs Dahn surgery upon himself. He walks into the bar, and the bartender, who does not recognize him since he is now a different manifold, serves him a drink. However, the bartender thinks he looks familiar, or at least locally similar, and asks, "Aren't you that sphere that just came in here?" "No, I'm a frayed knot."