The mattress salesman was always tired

This joke bounces right into classic wordplay, hinging on a single word with a double meaning. The setup paints a picture of a weary individual, perhaps someone who could use a good night's sleep themselves, despite their profession. The punchline, however, cleverly pivots, using the word "spring" to surprise us.

On one hand, "losing your spring" is an idiom for losing energy, vitality, or bounce in your step – which would make perfect sense for someone who's always tired. But then we remember he sells mattresses, and suddenly "spring" takes on a whole new, literal meaning: the essential coiled components that give a mattress its support and comfort. It's a neat trick that plays on both the salesman's personal state and the very product he's trying to move.