Open loops tend to take a lot of our short-term memory and so we get distracted by them even if they are not important. This is called the Zeigarnik effect. To solve this, we need to Close open loops by deleting them, doing them (if they are actionable; Two-minute rule), or deferring them, which involves writing them down in a system that we trust will remind us of them (i.e., Close open loops by externalizing them).
References
Ahrens, S. (2017). How to Take Smart Notes: One Simple Technique to Boost Writing, Learning and Thinking – for Students, Academics and Nonfiction Book Writers. CreateSpace Independent Publishing Platform.