When adding prompts to a Spaced repetition memory system, it’s usually a mistake to write prompts about a detail that seems interesting, but which is disconnected from everything else you’re thinking about. Spaced repetition memory prompts should connect and relate ideas—and it’s even better to make them connect and relate to ideas that you’re regularly thinking about.
“Orphan questions” (coinage per Michael Nielsen, 2018) cause two important problems:
At least for me, one common situation that often results in orphan questions is: someone shares an interesting paper in a field I know nothing about; I read it and write a few prompts. A few months later, I have no idea why I’m reviewing them. They don’t relate to anything I’m doing or thinking about.
Michael underscores the particularly harmful case of “lonely orphans”:
It’s particularly worth avoiding lonely orphans: single questions that are largely disconnected from everything else. Suppose, for instance, I’m reading an article on a new subject, and I learn an idea that seems particularly useful. I make it a rule to never put in one question. Rather, I try to put at least two questions in, preferably three or more. That’s usually enough that it’s at least the nucleus of a bit of useful knowledge. If it’s a lonely orphan, inevitably I get the question wrong all the time, and it’s a waste to have entered it at all.
Nielsen, M. (2018). Augmenting Long-term Memory. http://augmentingcognition.com/ltm.html