I see this dumb shit all over Facebook too.

I’ve always interpreted the stare as a consequence of growing up where cameras (phones) are everywhere and nothing ever disappears from the internet. And as a result people who grew up under that are ALWAYS cognizant of this. So they express nothing because it could make for embarrassing video or photos. Being extra or try-hard are also considered bad. Everything is tamped down, socially. They are seriously just repressed, internalized.