generated at
There are known knowns
知られていると知られていることがある
Black swan theory
Cynefin framework
Dunning–Kruger effect
Emic and etic
Epistemic modal logic
Four stages of competence
I know that I know nothing
Ignoramus et ignorabimus
Ignotum per ignotius
Johari window
Knightian uncertainty
Known and Unknown: A Memoir
Outside Context Problem
Russell's teapot
Undecidable problem
The Unknown Known
Wild card (foresight)

https://en.wikipedia.org/wiki/There_are_unknown_unknowns