The French have a great expression, "Avoir l'esprit de l'escalier" which translates literally to "the wit of the staircase." It is used to describe the perfect comeback that you think of too late to be of use, say, while you are descending the staircase while leaving the party.Yeah, we need that thread "Comebacks I wish I had thought of at the time"
I'd like to be quick-witted enough to tell the cancer survivor that I accept and appreciate her offer to donate on my behalf, and that I'd reciprocate with a donation in her name when the "Chronic Rudeness" telethon comes.