While originally used by professors of quantum physics to make sure students are understanding what they are talking about, it has evolved into a not so subtle way of insulting someone's intelligence.
A very annoying YouTube trend which involves editing a comment to make the replies of said comment look nonsensical and unrelated.
It sometimes can be used to try to make themselves not look like an idiot.
Comment: *An actual joke*
Author of comment: Nah...this looks too shit of a joke, lets change it!
Comment: I edited the comment so that the replies don't make sense
Common American phrase dating back to the late nineteen-hundreds. Very classy but also popular thing to say. Critically dubbed "meta-nationalist". Can be adapted to other countries.
You: Doesn't look like there's anything going on here today; the library's empty.
Alex: What? That does not make American sense. The calendar said today was supposed to be the Club Meet.