YSK about the "Frequency Illusion" : the reason why once you learn about something new, you suddenly start seeing it everywhere.
The Frequency Illusion is the cognitive bias that occurs after you first learn about a new concept, word, or idea, and then feel like you're suddenly encountering it everywhere. Think about it: you buy a new blue car, and suddenly you see blue cars all over the road. You learn a new word, and you hear it in three different conversations the next day. The world hasn't changed; your brain has. It's a two-part process: first, your selective attention is heightened for that new thing, and second, your confirmation bias kicks in, reassuring you that each new sighting is proof of its sudden ubiquity.
Why YSK: Because understanding this illusion helps you recognize it as a quirk of your perception, not a meaningful pattern or a sign from the universe. It can prevent you from drawing false conclusions, like thinking a rare problem is actually common just because you recently learned about it. It's a powerful reminder that your brain is not a passive recorder of reality, but an active filter, constantly highlighting what it considers relevant and ignoring the rest. This awareness allows you to question your own perceptions and seek more objective data before deciding something is a genuine trend.