When I was younger, I often met people who seemed kind of dim to me, at first, and later found the majority of them to be orders of magnitude brighter than me. It was not hard to connect the dots, the reason they were so much brighter was (in part) exactly because of what made them initially seem dim.. They asked questions, honestly. Not the showoff kind of question you ask to show how much you know, but real, honest questions that not only showed how little they knew, but importantly, allowed them to actually learn and understand, rather than just nod and not get it.

My intuition has changed from this, I find it that most times, when someone shows genuine interest and asks honest, revealing questions about some new topic, they often excel at many other things (and will likely on the new topic as well).

I'm adapting this myself, being honest, asking honestly, and sometimes looking really stupid (because, in that context, I am!), and I appreciate greatly both the wealth of information that allows me to access, and that almost anybody worth their salt recognizes this trait as well.

Failing an interview due to looking stupid is probably a blessing in disguise, you don't want to be hired by people who can't see this, and you don't want to work next to people who's just pretending to understand, not learning because they can't afford to look stupid when they are (and thus stay stupid, and be much more inclined to try to pass blame to someone else, like you, who look stupid).