My friend Lilah is the crunchiest person I know.

She refuses to kill bugs and rats. She once made me try her homemade wine (disastrous). A few years ago, she quit her food-justice nonprofit job to live in a yurt, and after that she went to grad school and moved into an attic, where her roommates were squirrels. Against her will, she did own an iPhone for a time. She had no choice: A university administrator explicitly told her she couldn’t perform her studently duties without one. Two-factor authentication and all that.

But Lilah’s Lilah, so upon graduation, she gifted herself a dumbphone. And boy was that phone dumb. Designed for those weaning themselves off the real thing, it connected to Wi-Fi but not to the internet, and it certainly didn’t accommodate apps. Lilah now navigates the world smartphoneless. “I think my main reason for getting rid of it was that I felt like my brain was being consumed,” she recently told me.

Most of my fellow twentysomethings want to go dumb like Lilah. I’m familiar with and sympathetic to the urge: I waste hours a day, and lose hours of sleep, to the tyranny of the scroll. I’m trapped in a shame spiral for spending so much of my precious life watching videos of complete strangers until my eyes sting and my head aches. And, ideologically, I like the sound of withholding personal data from corporations, of not succumbing to ads every time I unlock my home screen.

But I haven’t gone dumb, and the reason is simple: I’m terrified! Ditching my smartphone would be completely disorienting. It would significantly reduce my overall competence. It’s deeply embarassing—it really makes me feel like a giant baby—but I am certain that my smartphone is a part of me. I mean that literally: The panic I feel when I lose sight of it is visceral, existential, as if pieces of my physical body are missing.

This thought is neither insane nor original. Back in 1998, Andy Clark and David Chalmers introduced their “extended mind hypothesis,” the idea that external tools can extend, in an all but physical way, the biological brain. Checking the Notes app for your grocery list? Using Google Maps to get to a friend’s house? That’s not just your phone at work, and it’s also not just your biological brain—it’s a single cognitive system composed of both. Since the age of 14, when I got my first iPhone, my mind has welcomed Apple’s increasingly powerful operating systems and, over the years, fused with them. My phone and I are now totally, completely enmeshed.

But is un-enmeshment a worthwhile pursuit? And is it, as dumbphone users seem to believe, even possible?

In 1985, the late psychologist Daniel Wegner published a theory about intimate human relationships called transactive memory. He argued that long-term couples store information in one another and that their collective pool functions as something of a joint memory card, a single “knowledge-acquiring, knowledge-holding, and knowledge-using system that is greater than the sum of its individual member systems.” This is uncannily—maybe humiliatingly—applicable to my relationship with my iPhone.

At the end of my senior year of high school, I went to the Apple store to replace my worn-out device with a new and improved one. In classic irresponsible-teenage fashion, I hadn’t backed up my data from recent months, so my photos from that school year disappeared. My memories of that period, it turned out, disappeared along with them—a road trip across the South, a friend’s dramatic breakup. I knew, intellectually, that these things had happened. But I had no real feeling for them, no specific images to trigger my recollection.