“some people are too dumb to know they’re dumb, and end up thinking they’re smarter than smart people” is just obviously true.
I interpret imprecise colloquial statements like these not as weak claims about existence of such people but as bolder claim that the effect is of practical importance in the challenges faced by many people.
I interpret imprecise colloquial statements like these not as weak claims about existence of such people but as bolder claim that the effect is of practical importance in the challenges faced by many people.