As the decade comes to a close, social media is packed with nostalgic memes marking the end of the decade. On Twitter, people are humblebragging about their biggest personal accomplishments. (Mine is a tie between meeting a cat named Larry David and finally going to a Guy Fieri restaurant.) And predictably, on Instagram, people are posting side-by-side photos of their 2009 selves and their current selves.

Search the Instagram hashtag #2009to2019 or #10yearchallenge and you’ll notice bangs are out and flannel is in. But there are two basic changes related to technology that are easy to miss. The first is unsurprising: Image quality has gotten much better. The second showcases how our photo taking style has changed. While most people’s 2009 photos are obviously taken by someone else—full-body shots from a distance, often containing little bits of forearm or cheek that reveal friends or family cropped out—most people’s current photos are mirror selfies where their smartphone is visible, or a flattering front-facing camera snap. Just as video killed the radio star, the smartphone has largely replaced the stand-alone camera.

As our device of choice has changed, so has the way we take photos. Having a camera always in your pocket has allowed us to take photos of pretty much anything—the number of photos we’ve collectively taken doubled between 2013 and 2017, from 6 billion to 1.2 trillion. Plenty of ink has been spilled debating whether smartphones have destroyed a generation (depends on what you mean by destroy), changed our brains (technically, most things we encounter in life do this), or caused us grow horns (they haven’t), and similarly, the impulse to take selfies or record what’s happening is often dismissed as a narcissistic tendency, or a dangerous dissociation from the present. It can be those things. But it’s also an opportunity to capture your own life more honestly—a way to remember what you were really like in one season of life, the mundane food photos alongside shots of scenic vacations or birthday parties. The mundane things you use your phone to document are the details that add up to a full life, what it was like to be alive right then.

As I was looking through photos for the 10-year challenge, I accidentally undertook a 30-year challenge. I discovered that I’ve always taken a lot of photos. iPhoto tells me I have 38,123 photos and 1,446 videos on my computer alone. Of those, 1,129 are from before 2003, or what I would classify as the disposable camera era, back when you had to decide whether a particular shot was worth one of the precious 27 exposures you had at your disposal, pay to have your photos developed, and painstakingly scan them into your computer. Once my family bought a digital camera in 2004, I took 10 times more photos (11,994, to be exact) in the following six years. But a solid 60 percent of my photos (23,261, a horrifyingly large number) were taken after I got my first iPhone, around the turn of the decade.

This explosion of photos in the iPhone era was driven largely by convenience. Carrying a camera requires an explicit decision, and, for women, a commitment to carrying some kind of purse, because our pockets don’t accommodate most items. But it was a no-brainer that I’d need to carry my phone with me, and so it was always there when I wanted to snap a photo. Going through my archive, I noticed in the first few months of my iPhone use, I reserved my photo-taking for the same types of things I’d pull out a film or digital camera for: parties, vacations, bona fide events. But after a year or so, I’d started snapping photos of things that might not have risen to the standard of a film or digital camera shot: a counterfeit Canadian $5 bill next to a real one; what the board game Settlers of Catan looks like in French; a fire hydrant in Tahoe with a sign advertising that it was an ORIGINAL PROP in the Disney movie Shaggy Dog (weird flex, but OK). These photos would have fit right in on the subreddit Mildly Interesting—snippets of daily life that amused me slightly, but nothing to write home about.

I also noticed photos that would have been nearly impossible to capture on a real camera. I snapped a shot of some Mario Bros. graffiti in Oakland, California, I saw from a friend’s car, which was easy to do because I already had my phone in my hand. But had I not already had a camera in my palm, I probably wouldn’t have reacted quickly enough—or cared enough—to pull out a real camera.

If there’s one silver lining to our collective smartphone addiction, it’s the gift of perspective.

Because we are so often holding our smartphones, taking a photo with one is not only easier, but also more subtle than pulling out a camera. Whereas I might be self-conscious about drawing attention to myself by taking a photo of a train scene with a camera, I can sneak a photo with my phone while no one around me is the wiser. That’s led to dozens of photos I’ve taken in public of things I’d never dare pull off with a real camera: a man in a 10-gallon cowboy hat with a tie shaped like a giant cactus, a Ford Econoline with stickers reading “JEAN CLAUDE VANVAN,” good dogs on public transit. You can’t pretend to be checking your email or taking a selfie with a real camera, but you can with a smartphone, which means you can get away with creep shots.

By 2014, it became clear how much of my daily life I spent on my phone. My camera roll had become more than a photo album; it functioned also as a repository for random information, an extension of my brain. Some photos were meant to be a placeholder for my own memory—shots of PowerPoint slides at conferences, placards at public gardens with the names of plants I liked, receipts—while others were silly memes I’d liked and texted to friends. The result was an even fuller picture of my life—not just evidence of what I did every day in the real world, but also my digital world. By 2017, my photo albums included countless reaction GIFs, screenshots of games like Neko Atsume and my friends’ hilarious one-liners in WhatsApp, or moments I’d posted to Snapchat or Instagram, complete with the apps’ built-in geotags or commentary texts. Whereas years ago, the days in between photo-worthy events and trips would simply be blank, now they’re filled with the detritus of daily phone use.

Having this much detail about the past 10 years means not all the memories are happy. Whereas my photos from 2000–10 are mostly the high points of life, like graduations or proms and good times with friends, my smartphone camera roll gives me a more nuanced look at what’s happened: There have been fun weddings and beautiful hikes, but also a car accident and surgeries, sick days and dismaying political news. (I’ve taken and shared screenshots of the worst stories, of course.) If there’s one silver lining to our collective smartphone addiction, it’s the gift of perspective: Do you remember that selfie you snapped to distract yourself from how nervous you felt before going on stage for a talk, or that awful, mean email that upset you so much you needed to share it with friends so they could talk you down? Maybe you’d forgotten, but you got through it after all. Ten years from now, whatever you’re worried about now will just as distant a memory.

Future Tense is a partnership of Slate, New America, and Arizona State University that examines emerging technologies, public policy, and society.