Everyone acts like people should stick to their league assuming that people are aware of what their league is. This is absurd. People vastly overestimate their attractiveness and their intelligence and their competence in a given field. It's a survival mechanism ingrained in us.

And the more unattractive a person is, the less aware she/he is of her/his unattractiveness. There are even studies on this and similar phenomena. I'm too lazy to cite them, but if you want to argue and say that people are self-aware and that I'm wrong, bring it on and I'll cite the studies.

Younger people tend to be more self-aware. Male boomers are the worst. I see every day crusty, repulsive, old men hitting on very young women because they've been fed this lie that men age like fine wine and that women like old farts.

On a related note, I conduct job interviews as part of my role and candidates claim to be bilingual or even trilingual. I interview them in the languages they claim to have bilingual or trilingual fluency in, and they just know a few words. They don't even have a basic knowledge. Moral of the story, people are delusional and have no idea what their league is.