Zeigarnik Effect

Uncompleted tasks occupy our minds far more than completed ones — our cognitive system keeps unfinished business active, intruding on focus and sleep until closure is reached.

• Waiters remember every detail of unpaid orders with perfect clarity — and forget them entirely the moment the bill is settled.
• An unfinished project intrudes persistently into conscious thought during evenings and weekends — while a finished one disappears from mind immediately.
• Cliffhanger episode endings are psychologically compelling precisely because they leave the narrative loop open — the brain demands resolution.