๐Zeigarnik effect
Task occupies place in memory until it is done. Or until we write it down in a way that we think it will be dealt with.
It was inspired by waiters easily remembering details of still unpaid orders, but after orders were paid, they were unable to remember details anymore.
Applications
See also
Ovsiankina effect is often confused with Zeigarnik effect and explains that humans tend to return to interrupted tasks.