The bold year that was 2015 gave us innovations in UFO sightings and stunning TV characters — but if you want a pure, unadulterated look at our collective cultural id, look no further than Tumblr. Here’s a trip down meme-ory lane (we’ll show ourselves out) at some of the most reblogged memes of 2015 and what they say about us.

The Dress

In 2015, no mundane conversation got dragged out as far out of the mall as The Dress: Is it blue and black or white and gold? What started as an innocent shopping-opinion query from a Tumblr user transformed into a viral phenomenon. Debate about optics and perception raged on every corner of the known universe. Buzzfeed absolutely went to town on this sucker. But not even MIT was immune.

Surprisingly, The Dress is only No. 5 on Tumblr’s most reblogged meme of the year. Still, it provided an important lesson: dressing room debates aren’t just for your pals and a bored salesperson. The whole world cares. They really, really do.

Left Shark

Katy Perry’s Super Bowl halftime show — which featured a hallucinatory array of dancing objects and anthropomorphic animals, including two enthusiastically gyrating sharks — launched a thousand conspiracy theories, journalism profiles, and New Yorker features.

Again, a dissonance drove the discussion: That shark on the right is on point, but does that shark on the left even know what day it is? In the full video, the distinction isn’t as stark as the clueless moments the internet’s GIF makers found.

Shockingly, this is only the 15th-most reblogged meme on Tumblr’s list. In 2015, when music is produced, choreographed, and micromanaged to the nth degree, it’s the reassuring capacity for human error that captivated us.

PSAT

Is there a more frustrating test in existence than a test that’s just practice for another test? Nope. Do teens who have to take it realize it? You bet.

Teens brought their anxiety about the PSAT to the internet this year, and it spread to become the ninth-most reblogged meme of the year. Even with all the anxiety about Teens Today the social media age has not changed the fact that teens recognize when they’re spinning their wheels in the mud, and they don’t appreciate it.

Pepe the Frog

Pepe the Frog is a deceptively simple meme: He’s not a dress that provokes debate on the nature of optical illusion and attention-policing nor is he an anthropomorphic shark who apparently missed rehearsals. He’s a reaction meme in the same vein as the Condescending Wonka meme or the Sean Bean “one does not simply…” meme.

And yet, Pepe’s very simplicity is what catapulted him to the top on Tumblr’s reblogged memes. The guy has been around, in internet years, practically forever; 4chan users have been deploying him since 2008. He may be a frog, not a chameleon, but he’s got a face for every situation and internet browsers can see whatever they want to in his green cartoon visage.

What memes, from the mundane to the absurd, might set the Tumblr-sphere alight in 2016? For now, Gritty Bill Nye looks like an early contender.