Full disclosure: I am, in fact, an adult. But, that doesn't mean that I don't want to be cool, or at least know what the cool kids consider to be cool. (Boy do I hope saying the word "cool" is cool.)
Adults and teenagers are supposed to have different interests. We like wine, they like wine coolers. We like bibimbap, they like K-pop. We like making fun of Justin Bieber, they like, well, Justin Bieber. But, after combing through this thread ad nauseam, in which thousands of teenagers post lists of what they're into, I've come to the startling realization that teenagers and adults like the exact same things.
The most common unifier here is Snapchat, the time-sensitive photo sharing app that Facebook tried to purchase for $3 billion. Now we know why. Facebook's decline in popularity is apparent, especially among teenagers who prefer the immediacy of Snapchat, Instagram, Twitter, Vine, and the hipster cache of Tumblr. But, teenagers aren't the only ones giving Mark Zuckerberg and co. the cold shoulder in favor of flashier ways to overshare. Personally, it seems my friends don't use Facebook anymore, except to share news of their newborns passing gas for the first time. Um, no thanks. I'll take a self-destructing selfie with the caption "time to get turnt" any day.
Other than social media, teenagers apparently enjoy going to the gym, drinking, and having sex. That's pretty much all anyone I know does. These are timeless activities centered around vanity and pleasure. They were popular when I was was a teenager, and will likely be popular when my teenager's teenagers are teenagers, although the sex will happen somewhere in space and going to the gym will be an Oculus thing.
Teenagers also think tattoos, Ray-Bans, Converse, Vans, and skinny jeans are cool. So does everyone in Brooklyn. Teenagers like iPhones. I've considered getting mine stitched to my hand. In fact, the only trends that seem unique to being a teen are EDM, Ripcurl, and Macklemore. EDM is kind of loud, I had to Google Ripcurl, and I still think Macklemore robbed Kendrick at the Grammys.
Maybe being an adult isn't so bad after all.