Millennials are turning 40 — and it's freaking them out

Everybody is at least a little scared of turning 40. Well, maybe not everybody, but the conventional wisdom is that many people stare down their fifth decade with a touch of dread. Reaching a new decade is always weird. Turning 30 says "adult." Hitting 50 means you're officially AARP-eligible. At 40, it's so over. You're middle-aged, and the wear and tear of life is almost certainly taking its toll, no matter how faithful you've been to your strict skincare regimen.

As millennials approach the milestone, things look a bit different than they did when our baby-boomer parents reached it and declared themselves "over the hill." (I'm a millennial, so I'm using "our" here.) Forty is supposedly the new 30. The start of middle age no longer means sending your kids off to college, getting a divorce, or buying yourself a Corvette. The modern 40 means having toddlers running around, buying your first home, and, at last, catching up on retirement savings. Or looking around and wondering whether some of those life touchpoints passed you by.

"Things happen in midlife that you may not be prepared for. One is simply that aspirations align with reality," said Carol Graham, a senior fellow in economic studies at the Brookings Institution who has studied happiness (and unhappiness) and aging. "By the time you're 40, 45, you can't sing, and you can't play guitar; maybe it's time to give up on your aspirations of being a rock star."

Whether you're prepared for it or not, 40 hits differently — culturally, physically, emotionally. You find yourself in the "sandwich" phase of life, managing care for your children and your parents in a body that, as much as you hate to admit it, doesn't work as well as it used to. Suddenly, everyone around you is talking about the importance of weightlifting, lest you fall apart, and debating whether to keep up the dye job or give up the game on the grays. For women, fertility is waning, and menopause is on the horizon. Is that 3 a.m. insomnia the result of stress about your kid's report card, a classic case of existential dread, or a symptom of perimenopause? At work, you realize you're protected from age discrimination, which you feel like you're still much too young for. But now that you think of it, you did take your graduation date off your LinkedIn profile a while back. It just seemed like a good idea.

Forty is an arbitrary number, and there's nothing particularly horrifying about it. Nevertheless, for a lot of people, it's terrifying. And millennials — a generation that once embodied youth — are knocking at 40's door, if they're not there already.

One reason 40 seems daunting: The decade of life ahead is, scientifically speaking, supposed to be miserable. Academic literature on happiness generally suggests that our satisfaction with life as we age is U-shaped. When we're young, we're happy — and then that declines, bottoming out in middle age, about 40 to 50. (The low point is 47.2.) As we pass middle age and get older, we get happier again.

Hannes Schwandt, an associate professor of human development and social policy at Northwestern University, told me that midlife nadir is like a "biological regularity comparable to a second puberty." It's caused by unmet expectations and aspirations that are painful in midlife but, as his research has found, "beneficially abandoned and experienced with less regret during old age." Basically, your 40s have a "this is it?" vibe that can be upsetting but that fades as you get older, accept things, grow to appreciate your relationships and experience, and get back some independence as your children age.

"When you're young, you are typically overestimating what you're getting in the future. When you get married, you think that your marriage will last; you don't think that there's a 30% chance you'll be the one that is divorced," he said. "Not everything turns out as nicely, and this can then be just accumulating disappointment."

Schwandt added that disappointment leads people to revise their expectations and have a less rosy outlook about the future, so they land in "double misery" territory. The good news is that it gets better. The bad news is that it takes time to figure that out.

Millennials were born from 1981 to 1996, so everyone in the '81-to-'84 range — millions of members of the "avocado toast" generation — has hit 40 or is about to in the next couple of months. Millions more will do so over the next decade. Many are turning 40 having only recently reached typical adult milestones, or having accomplished less than they might have expected. The delays mean the "huh?" aspect that comes with the start of middle age has been redefined.

"People are getting married later and having their kids later and settling into careers later, and so they may be thinking, 'Man, when my parents were 40, they'd already been married for 15 years and had completed their family and been working in a career for 20 years, and that's just not where I am,'" said Jean Twenge, a psychologist who wrote the book "Generations: The Real Differences Between Gen Z, Millennials, Gen X, Boomers, and Silents — and What They Mean for America's Future."

Delayed development isn't all bad — having kids later in life when you're more established in your career might remove some financial stress, for example. Millennials are more likely than Gen Xers and baby boomers to have a college degree, and, despite the stereotype, they're wealthier than prior generations were at the same age. Life expectancies have increased from where they were decades ago, so 40 isn't as "middle-aged" as it used to be (or at least that's what I'd like to tell myself).

Schwandt is 42 and the parent of two young children himself. He posited that delayed development might actually ease some of the midlife crisis, or at least put it off, because people simply don't have the space to sit back and reflect and wonder what might have been.

"There are many worries and many issues, but I don't even have time to think about those questions," he said. "Once things settle a little bit, the dust settles, then you think, 'Hey, what am I doing? Where am I?'"

The upside is that as you get older, you become wiser and better able to handle life hiccups. What felt like a disaster at 20 does not feel that way at 45 — you understand that this, too, shall pass.

"By the time you get older, you've gone through a lot of bad experiences, and they're not always pleasant, but unless you get really ill and die or you have a really horrible shock, you realize you can get over it," Graham said.

Justin Balik, 36, a climate-policy director in New Jersey, told me that one thing that freaks him out about staring down 40 is seeing his first gray hairs, an experience he finds "a little bit terrifying." Bigger picture, it's been jarring to realize there aren't really adults in the room to fix everything — behind the curtain, the Wizard of Oz is just another uncertain person trying to figure it out.

"When you're younger, you assume that there are people that are smarter than you and that have figured it all out and are working on something," he said. "It turns out that it's just up to all of us, collectively."

Kelly, a 39-year-old fundraiser in Massachusetts, has been doing a lot of reflecting ahead of her 40th birthday. She's been journaling about it, talking to her therapist about it, and reading "All Fours," a book about a woman in her 40s. She's not so worried about her fertility — she has a son, and she's a one-and-done mom — but she's aware that her body is changing, as is, maybe, her place in society. There aren't a ton of great examples in popular culture of what her 40s are supposed to look like — the movie "This Is 40," she supposes, or "Father of the Bride," maybe. She remembers the stupid "over the hill" birthday cards her parents got when they hit the milestone.

"I feel like I'm on the cusp of something, and 40 is that cultural touchpoint for it," Kelly told me. She asked for her last name to be withheld to protect her privacy.

Many of the anxieties about turning 40 aren't unique, but Kelly can't help but wonder if she would feel better about it had the pandemic not happened, with the associated lockdowns and workforce upheaval and inflation. It stole the end of her youth. "I didn't get to just gradually and gracefully move into midlife," she said. "There's a bit of the arrested development that kind of came from this extenuating circumstance and not this internal thing."

I would be remiss not to acknowledge that the experience of 40 is different for women than it is for men. It's not just that things change physically for women as they get older — they change culturally, too. We put a premium on youth and beauty, especially for women, and as they age, many feel like they're treated as invisible. The antiaging industry targets all genders, but it's mostly women who get told how to stay young.

Kelly is lucky that in her field of work, being a little older is a bonus. She has friends who work in tech — a youth-oriented industry — who are struggling to find jobs. They're not making it past interview rounds they're sure they would have flown through five years ago. Maybe that's attributable to a tech-industry hiring slowdown, but they wonder if it's their age. "We're actually having a lot of those conversations about how you have to kind of remove years from your résumé and don't put your graduation date on," Kelly said.

The internet, too, gives aging nowadays a different flavor. TikTok and Instagram put generational debates front and center, with Gen Zers and millennials jousting over hair parts and sock lengths and jeans widths. We're also staring at our aging faces a lot more thanks to Zoom and the ubiquity of cameras in our lives. It makes it easier to compare ourselves to one another. The question isn't just whether my 40 will look like my parents' 40 — it's also whether it will look like the 40 of everyone from my high school.

"Now you're comparing your 40 to your quote-unquote friends' 40 online through Facebook and Instagram and Snapchat, whatever it may be," said Lindsey Anderson, an associate professor at the University of Maryland who studies aging. You're also aware they're looking at you. "I do think that there's also this increased, maybe, feeling that if you fail in some way, people — it's going to be very visible as well," she said. "Also, I mean 'fail' very much in quotations, because what failure is is really subjective."

Aging means moving out of that coveted 18-to-34 demographic that culturally sets the tone on what's cool. There's also no way to sugarcoat the fact that part of aging is decline, decay, and, eventually, death.

The story around 40 isn't all doom and gloom for millennials. Because life expectancy is longer and people are taking their time in getting around to "adulting," the story of the 40s is one of extended youth more than a transition into old age. People take better care of themselves these days than they did, say, 50 years ago, so while you can't turn back the clock, those years of slathering on sunscreen do pay off.

It's also important to remember that 40 is a random number, Anderson said. "It's all arbitrary," she said. "People age differently."

People experience the middle-age dip in happiness differently, too. Those who tend to have a more positive disposition generally have a smoother go of it. Graham, from the Brookings Institution, told me that the U-curve story might be changing — and for some reasons that are quite disturbing. It's not that midlife has gotten easier (sorry, millennials) but that young people are unhappier now, too (really sorry, Gen Z).

"It's much harder to even think about what is going on in terms of youth unhappiness now, but it's to the point that they don't start higher. So it's not really great. In fact, they may be happier in midlife than they are as youth," she said. "The easy explanations like social media or COVID — they exacerbated something deeper going on, and I don't think we have a full handle on it."

It's not clear whether today's young people will buck the trend and become happier as they age or become even unhappier. Turning 40 could be worse for Gen Zers than it is for millennials.

I'm a little too close to 40 for comfort, and I was hoping this story would make me feel better. It did, to some extent, in that at least I'm (probably) going to get there, and I have really been good about sunscreen. Plus, after that midlife dip, things get better.

"You have fun again later," Graham said.

Emily Stewart is a senior correspondent at Business Insider, writing about business and the economy.