Playing billiards and having tons and tons of books. I also forgot to add chess in particular.
People can possess enormous collections of books, and do, but I really bet them that they don’t pick up to read a single one. Only to sometimes bring up certain lines to win online and pointless arguments over.
Billiards is usually a bar/pub kind of game, but some others seem to associate it with intelligence. You don’t need to be intelligent to play billiards.
Chess is self-explanatory. Lots of people throw around the line of “people are playing checkers while X plays chess” and other similarities. I think people look way too into chess as being a measurement of intelligence.
Eyeglasses are an interesting case, because there seems to be a causal relationship between being nearsighted and staying inside a lot as a kid, which used to be mostly people who read books or just spend a lot of time on school work. That’s less relevant now that kids stay inside to watch TV, play videogames or scroll on their phone, though. Also, many people who need glasses either didn’t have the means (e.g. no access to eye doctors, no money for glasses; probably not as important nowadays in most wealthy countries) or choose to not wear them due to vanity, and both of those reasons are kind of orthogonal to adjectives like “intelligent” or “intellectual”.