Not sure if it has a name but often there’s a trend of “one thing leads to another” related articles on the HN front page.
Yesterday there was something similar that might have planted a seed in your mind like it did for other people.
I definitely noticed this trend of article chaining, bu it must have been something else in this case, because i have absolutely 0 memory of seing that post yesterday. Actually, i think my thought came from an instagram video in my feed of a guy showing human division algorithm using sticks on a whiteboard.
or probably just some kind of preference/selection bias.
You own a red Mercedes now and suddenly you see only red Mercedes' on the streets.
Right. Or it could be frequency illusion. Once you become aware of something, it appears to be more frequent:
https://en.wikipedia.org/wiki/Frequency_illusion