The class of 2015 grew up listening to Britney Spears and NSYNC. We watched Lizzie McGuire and Even Stevens for guidance about what to do during those awkward middle school years. We had multiple sing-a-longs with our friends while watching all three installments of “High School Musical,” and we cried a little bit when we found out that people didn’t really break out in song and dance in the high school hallways.

It’s crazy to think that while we were having these experiences, others were having the same experiences, but in different times of their lives. There were college students jamming out to Britney in their dorms while we were singing her songs on the playground. There were kindergarteners swooning over Troy Bolton/Zac Efron while we were convinced that we actually had a shot at marrying him.

Looking back at these past four years of college, I compiled a short list of big phenomena that we experienced each year in college that graduating seniors four years ago never had the pleasure of knowing.

FRESHMAN YEAR: “The Hunger Games.” Yes, the first book was published in 2008, but since the first movie didn’t come out until this year, it didn’t gain any hype until then. You may have been one of the people who dressed up in full costume for the midnight premiere, or one of the several girls who braided her hair like Katniss. Team Gale or Team Peeta was a hot topic of debate, and many friendships were tested because of it. GPAs plummeted as countless people stayed up late reading the books from start to finish over the course of only a few days.

SOPHOMORE YEAR: Snapchat. Before sophomore year, very few people even knew what Snapchat was. I remember the first time my RA told me about it, and I thought it was the stupidest idea ever. Why would I want to send pictures of myself to my friends that they can only see for three seconds and then never see again? That seemed like such a waste of my time and theirs. But now, I cry inside whenever a snap-able moment passes by and I forget to capture it to add to my Snapchat story—or when I send a Snapchat before adding the perfect emoji.

JUNIOR YEAR: “Frozen.” I saw this movie in theaters with my friends who had already seen it twice, and they were singing along to all of the songs already. The number of hours I spent watching renditions and YouTube videos of “Frozen” songs is unreal, and was also probably very detrimental to my GPA. The phrase “let it go” will never be the same again.

SENIOR YEAR: Taylor Swift Mania. Okay, we all either loved Taylor Swift or hated Taylor Swift before this year. But once her latest album, 1989, came out in October, I saw so many people switch over from hating her to loving her—or at least loving her songs. People were shaking it off like never before, and writing names in blank spaces like crazy. If you haven’t switched over to the dark side yet, good for you. But just wait, because your time is coming.

It’s crazy to think that we will always relate these pop culture crazes to our college experience, while there are 10 year-olds out there who will always relate it to elementary school. If that doesn’t make you feel a little bit old, turn on Disney Channel and see how the stars of all the shows are now almost 10 years younger than you. Where did all the Hillary Duffs and Raven-Symones go?