The Zeigarnik Effect is a psychological phenomenon which describes the tendency of people to remember current or incomplete tasks/ events more easily than those that have been already completed.
One of the most common usage of Zeigarnik Effect is the ….”To be Continued” … the next episode of a TV serial or the Movie…
In the 1920s, Ms Bluma Zeigarnik, a psychiatrist and psychologist, who demonstrated this effect, observed that the waiters in the restaurant she and her friends were dining were very easily able to remember the orders of the customers of which some were very long and complex. They never made any mistake, however once they delivered the order they could not remember anything about the customers they served.
After a detailed study on children and adults Zeigarnik found that people remember details of the current task more than the completed tasks.

Studies have shown that as a task is being carried out, the mind develops a task-specific tension, which helps the brain to remember/ recall any relevant information. It remains in the mind till the task is completed.
Zeigarnik effect can help us to enhance :
· Self motivation
· Memory
· Time Management
· Confidence
· Self Esteem
Resources
https://www.goodtherapy.org/blog/psychpedia/zeigarnik-effect
Remembering and Regretting: The Zeigarnik Effect and the Cognitive Availability of Regrettable Actions and Inactions, Savitsky, Medvec and Gilovich