Clash of the micro-generations

There is a phenomenon I've noticed over the years, among a small but significant minority of my slightly older acquaintances (but thankfully none of my friends, and thankfully not recently, perhaps because I'm now old), that goes as follows:

Forgetting that they too, at 18 or 23 or whatever were single, unmarried, or childless, they act as though people they meet who are a few years younger are somehow behind in things, or making some kind of counterculture statement, by not having already settled down, "settled down" as defined by whichever criteria they happen to have met themselves. (As in, if they're cohabiting, you're odd for being single. If they're married, you're odd for just monogamously dating. And so on.) As though you, the younger person, don't have it together enough to have three kids and a house in the suburbs, when the relevant fact is that you're, for example, a junior in high school.

Why this happens, I think, is that when interacting socially, people 16 to 30 (give or take) can feel, in many ways, like about the same age. You connect over whatever you have in common, which makes you assume you're basically coming from the same place, which makes whatever differences you do discover seem like they stem from personal quirks, rather than from life stage. Life stage can be especially tough to assess in the recent-college-grad years, when technically one can be married with kids without this being scandalous, but not too many are. Another possibility is that 18 looks awfully appealing (to some) at 30, so pretending as though an acquaintance's failure to be settled down at 18 is a character flaw and not evidence of youthful freedom is some kind of compensation. Really, who knows why it happens, but it does.

I was reminded of this phenomenon by Daniel Engberger's Slate piece saying one must allow plus-ones at weddings, whether or not those plus-ones are known long-term partners. I agree with him, but for a slightly different reason. Reason being, to a couple about to wed, the relationships that slightly younger friends (or, and I should have made this clear above, friends the same age but for educational or personal reasons at a slightly different life stage) are in seem, by definition, casual. The more serious a person is with a partner, the more fleeting and hook-up-like others' non-marital relationships appear. And it seems trashy and wasteful to invite a fling to a wedding. Meanwhile, "fling" is in the eyes of the beholder. If brides-and-grooms-to-be remembered that their own situations did not, except among the very traditional, begin as "serious relationships," they might realize that the youngsters who they can't believe want to bring a date are nothing more rebellious than younger versions of themselves.