have the brains of goldfish
More on that point. People also seem to believe people are generally like the people they associate. Was discussing this with the oldest not long ago, because she things people are generally different than i think they generally are. Said the majority of people I associate, I would consider them to be a similar intellect to myself or greater than. Have had the impression people of her intellect generally view everyone else as stupid, because by comparison maybe they are, but she doesn't see people that way because she generally associates with people on the same intellectual level.
A big issue these days is that people generally consume media that reinforces their political views and their biases, and also discuss political issues with people who share their views and biases.
Your oldest may need to get outside her bubble of intelligent and well-informed people in order to see just how many extraordinarily stupid people there are out there.
It wasn't really a conversation of realizing how dumb other are, but rather acknowledging how intelligent she is. She's one of those freakishly smart people, in a career surrounded by other freakishly smart people, utterly embarrassed by the word genius.
"Freakishly smart" is very subjective. I had a manager about 12 years ago, in terms of her IT role she was one of the dumbest people I have ever encountered. Seriously. Absolutely clueless about the business functionality that we were working on. I remember her coming to me one evening at work, after 5, she was working on something not-work-related involving some formulas and symbols I had never seen before, and she couldn't figure out how to enter them into a PowerPoint presentation.
I suggested that she take a partial screenshot and paste that into the PowerPoint, problem solved in about 5 seconds.
I found out later that she had a PhD in astrophysics, so the PowerPoint must have been in relation to that.
One of my friends at school was smart, certainly not freakishly smart but he was smart enough and he had a passion for science. I saw him on TV about 30 years after high school, not having heard a thing about him in that time. He was on a documentary about exoplanets, he was a professor of astrophysics at a big university.
My youngest brother is one of only a couple of people I would consider to be freakishly smart. He did well at school, got a scholarship, did well at university, bummed around and couch surfed for about 20 years without ever getting a job, and eventually became a life coach so he could teach people to make the most of their abilities and lead successful lives.
My ex-girlfriend (the other freakishly smart person I can think of) was cherry-picked from university (where she had 2 scholarships and completed a 4 year degree in 3 years while working full time) to work for a big consultancy, the young people she worked with were very smart but I remember a couple of them whispering to me "you know Susan is a genius?". She had more than her share of struggles but had the good sense to marry into money (i.e. not me). Last time I chatted to her she was nearing completion of her PhD about the holocaust.