“Spirit of the staircase" or "Staircase inspiration”
L'esprit de l'escalier
This phrase is a famous allusion to the witty remarks one thinks of when it is too late, as when one is leaving a meeting and going down the stairs. Paradoxe sur le Comédien (1773-1777)
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L'esprit de l'escalier
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Denis Diderot 106
French Enlightenment philosopher and encyclopædist 1713–1784Related quotes

“Faith is taking the first step even when you can't see the whole staircase.”
Variant: Take the first step in faith. You don't have to see the whole staircase, just take the first step.
Source: Let Nobody Turn Us Around: Voices on Resistance, Reform, and Renewal an African American Anthology

“Many a man may look respectable, and yet be able to hide at will behind a spiral staircase.”
Sunset at Blandings (1977 (posthumously published))

“I have the ability to pick stones thrown at me to build a staircase to climb up.”
Quoted from Lok Sabha Election Results 2019: Rise and rise of Prime Minister Narendra Modi https://indianexpress.com/article/india/narendra-modi-lok-sabha-elections-2019-result-bjp-congress-seats-counting-5745459/

Variant translations: Are you really sure that a floor can't also be a ceiling?
I can't keep from fooling around with our irrefutable certainties. It is, for example, a pleasure knowingly to mix up two and three dimensionalities, flat and spatial, and to make fun of gravity.
1950's, On Being a Graphic Artist', 1953
Context: In my prints I try to show that we live in a beautiful and orderly world and not in a chaos without norms, as we sometimes seem to. My subjects are also often playful. I cannot help mocking all our unwavering certainties. It is, for example, great fun deliberately to confuse two and three dimensions, the plane and space, or to poke fun at gravity. Are you sure that a floor cannot also be a ceiling? Are you absolutely certain that you go up when you walk up a staircase? Can you be definite that it is impossible to eat your cake and have it?

Narrator, p. 168
Sharpe (Novel Series), Sharpe's Enemy (1984)

K. Balachander, in p. 14
Rajinikanth: A Birthday Special (12 December 2012)