esprit de l’escalier

Careful as they may be, developers of Eiffel libraries will always run into cases in which, after releasing a library class, they suddenly experience what in French is called esprit de l’escalier or wit of the staircase: a great thought which unfortunately is an afterthought, like a clever reply that would have stunned all the other dinner guests — if only you had thought of it before walking down the stairs after the party is over.

~ Bertrand Meyer (1950 age:67) 1989, creator of design by contract and the Eiffel language.