I expect my 12 yr old nephew’s school to be a mix between dabbing (still) and bottle flips to “do you know da wae” and clicking, which is a dead meme on the internet but schools are usually behind. So that’s a range of about 2 yrs of memes.
Grown adults who reference memes? I expect a certain segment to make vine references irl.
That could work, sort of a “do you remember?” thing. Lets see, I’m 45, soon 46, so I guess I could reference 80s nostalgia and jokes. But I was never much for “in joke” stuff even then.
Memes are any social thing that’s short that spreads and morphs quickly.