We all know the noun adult. But I was perplexed last year to hear the new verb to adult. In social media, especially on Twitter and Instagram, it birthed a new hashtag: #adulting. As in: “Just paid this month’s bills on time #adulting,” or “Decided I couldn’t watch Netflix 8 hours straight and went to the grocery store instead #adulting.” It even got a nomination from the American Dialect Society for the most creative word of 2015.

“Adulting” is an ironic way to describe engaging in adult behaviors, like paying taxes or doing chores—the sort of mundane tasks that responsibility demands. To a growing number of Americans, acting like a grown-up seems like a kind of role-playing, a mode of behavior requiring humorous detachment.

Let me be clear: This isn’t an old man’s harrumph about “kids these days.” I still remember Doc Anderson standing in the street in 1988, yelling at me to slow down as I drove through his neighborhood in our small Nebraska town. I was 16 and couldn’t stand that guy. Years later, when I had children of my own, I returned to thank him. Maturation.

What’s new today is the drift toward perpetual adolescence. What’s new is seeing so much less difference now between 10-year-olds and young adults in their late teens and early 20s.

As many parents can attest, independent adulthood is no longer the norm for this generation. Data from the Pew Research Center show that we crossed a historic threshold last year: “For the first time in more than 130 years, adults ages 18 to 34 were slightly more likely to be living in their parents’ home than they were to be living with a spouse or partner in their own household.” Fully one-quarter of Americans between 25 and 29 live with a parent—compared with only 18% just over a decade ago.