I found a twenty-dollar bill on the sidewalk.

This joke cleverly plays on our expectations and then delivers a delightful dose of absurdity. The initial setup creates a relatable scenario of unexpected good fortune, leading us to anticipate a simple story of finding some cash. The punchline, however, executes a perfect bait (Review)-and-switch, replacing the promise of value with something utterly useless and nonsensical.

The humor truly lands in the sheer ridiculousness of a "coupon for a twenty-dollar bill." Money itself is already a universal medium of exchange, so the idea of a coupon for it is inherently redundant. Adding the detail that this already absurd coupon is "expired" simply piles on the comedic futility, tapping into the relatable frustration we've all felt when a promising discount turns out to be past its date. It's a playful jab at the value we assign to both currency and the fleeting nature of promotional offers.