Zeigarnik effect

The Zeigarnik effect states that people remember uncompleted or interrupted tasks better than completed ones.

Russian psychologist Bluma Zeigarnik first studied the phenomenon after noticing that waiters seemed to remember orders only so long as the order was in the process of being served.

Some suggest that students who wish to remember material better should leave learning unfinished when taking breaks, according to the effect. It is also suggested that the effect is behind the cliffhanger plot device.