Zeigarnik effect.

“Unfinished” tasks occupy short-term memory until completed or clearly delegated. Documented by a Russian psychologist who observed that restaurant staff could remember orders perfectly but immediately forgot patrons afterward.rA2

  1. Sönke Ahrens, How to Take Smart Notes: One Simple Technique to Boost Writing, Learning and Thinking: For Students, Academics and Nonfiction Book Writers (North Charleston, SC: CreateSpace, 2017). (See notes.)