For a few years now, evidence has been accumulating that millennials contain within them a weird combination of grandiosity and inability to leave the house — they’re self-absorbed and global-thinking, smug and terrified. But what if we’ve been blaming the wrong people? Now there’s cause to believe the worst people in America aren’t millennials. They’re millennials’ parents.

A clue lies in the verbification of the word “adult.” Millennials are shamelessly signing up for “adulting” classes to teach them how to be grownup. Why didn’t we ever need to use “adult” as a verb before? Simple. All of youth was spent taking responsibility, learning to be independent, achieving maturity. Adulting was simply growing up. You were mature long before you were an adult.

Not anymore. Today’s young adults seem baffled and overwhelmed by ordinary grownup stuff (see the video “Stressed Out” by Twenty One Pilots — the Crosby, Stills and Nash of the participation-prize generation). “I see a lot of suffering around not knowing how to do the ‘adulting’ thing,” Maine psychotherapist Rachel Weinstein told the online magazine Quartz. Along with elementary school teacher Katie Brunelle, she created the Adulting School, which pitches itself with these words: “We know you’re sick of feeling like you’re pretending to be a grown-up and that someone’s going to realize you don’t know the sh%#t you’re supposed to know.”

The Adulting School sets out to teach basic stuff. Really basic stuff: The first item on the “Adulting Quiz” (which is not a quiz but a series of statements to which the respondent is supposed to answer yes or no) is “I know how much money I have and how to access it.” Another is, “I’m comfortable following recipes.” Another is, “I know when to use which form of correspondence . . . for example, I wouldn’t break up with someone over a text.” Jeez, in my day, everyone knew the proper way to dump someone wasn’t via text: It was via ceasing to return phone calls.

Classes, in five categories (health, home repairs, etc.), are $19.99, so it’s not like adulting school is a big commitment. You can always go back to your juice boxes if you get too stressed. But what’s the point of making fun of millennials? If you grew up not knowing how to access your money, hang a picture or check the oil, maybe you’re not the one to blame. Parents of millennials — did you think you were doing your kids a favor by swathing their childhoods with bubble wrap?

“Almost everyone interesting I’ve ever met has a substantive and passionate answer to the question, ‘What was the first really hard work you did as a kid?’ ” notes US Sen. Ben Sasse, a former university president in Nebraska, in his upcoming book “The Vanishing American Adult: Our Coming-of-Age Crisis — and How To Rebuild a Culture of Self-Reliance” (St. Martin’s Griffin). “Bizarrely,” he continues, in the book to be published in May, “our culture is now trying to protect kids from similar hard experiences. We should be running in exactly the opposite direction . . . They need to know in their hearts and in their bones that suffering is not something to be avoided, but conquered.” Teach a kid to triumph over real problems, and suddenly following recipes seems like a manageable ordeal.