Better late than never

Only five years after retiring from my day-evening-and-weekend job as director of a library, I finally came up with the answer to the Gasbag's query:  "Do you know who I am?"

"Obviously you are nobody, because if you were someone I could be expected to recognise I would have recognized you."

Now I'll never get to say it.  Sigh.

The French call it l'esprit d'escalier, or staircase wit.  You think of the proper riposte on the way down the stairs, going home.