Zeigarnik effect

Etymology

Named for Soviet psychologist Bluma Zeigarnik, who in 1927 tested an observation attributed to Kurt Lewin: waiters recalled unpaid orders sharply until the bill was settled, then forgot them. Her experiments confirmed that interrupted tasks lingered in memory more than finished ones.

noun · /zy-GAR-nik ih-FEKT/
The tendency to remember unfinished or interrupted tasks better than completed ones.
What it names
Why the email you didn’t send keeps nagging while finished work vanishes from mind — open loops hold onto attention.
Example
Cliffhangers weaponize the Zeigarnik effect — the unresolved episode stays lodged in your head all week.
Related idea
It underlies the ovsiankina effect, the related pull to actually resume an interrupted task, not merely remember it.