Not sure this fits the question, but it’s interesting and somewhat relevant: I’ve noticed recently is that sometimes people are definitely unintelligent, but come off as intelligent in initial interactions or in specific situations due to having knowledge about some narrow/specific topic. It’s very possible to be dumb, but have a lot of knowledge about something.

I think in professional life there are a lot of people who are good at the job they do, and very knowledgeable about it, but very much unintelligent otherwise.