Curse of Knowledge
Etymology
The phrase was coined by economists Colin Camerer, George Loewenstein, and Martin Weber in 1989, studying how informed traders failed to price in others’ ignorance. It was later dramatized by the "tappers and listeners" study, in which people tapping a familiar tune wildly overestimated how easily strangers could name it.
noun phrase · /KURS uhv NOL-ij/
The difficulty, once you know something, of imagining what it is like not to know it.
What it names
Why experts write baffling instructions and forget how they learned — the knowledge in your head quietly reshapes your sense of what is obvious.
Example
The onboarding doc was written under the curse of knowledge — every "simply" hid three steps no newcomer could guess.
Related idea
Hindsight bias distorts your memory of the past; the curse of knowledge distorts your model of another person’s present mind.