Have you ever thought of the perfect comeback to a cutting remark—only to find you’ve missed the moment? Too late, you come up with the witty retort that would have silenced your catty interlocutor; the words arrive only as you leave the party, or when you get home, or as you sit bolt upright at four in the morning. 

You might be relieved to know you are not alone. In an episode of the American sitcom Seinfeld, George Costanza spends days trying to recreate an encounter, having missed the opportunity to respond to a remark by a co-worker. Plagued by the failure, he takes a three-hour flight in an unsuccessful attempt to make the perfect comeback.

The French call the phenomenon l’esprit d’escalier, or “staircase wit,” a term that has its origins in an essay by the 18th-century philosopher Denis Diderot. He describes feeling so overwhelmed during a conversation at the home of an important statesman that he was only able to gather his wits as he was leaving (at that time, reception rooms were on the second floor, meaning that Diderot would have to go downstairs in order to leave). Ironically, Diderot’s essay “Paradox sur le Comédien” wasn’t published until 1830, 46 years after he died.

It's an idea that has equivalents in other languages: The Yiddish term is trepverter (step words); in German, it’s treppenwitz (staircase wit). In a play on the idea, the philosopher Friedrich Nietzsche uses the term treppen-glück—which translates to “staircase happiness” to describe the experience of only being able to enjoy an event, or even a whole period of your life, after it has happened.