This weekend was my son’s third Halloween. And, for the third time, he was dressed up as a pop culture character. As a baby, he was Yoda. As a one-year-old, he was Belkar from Order of the Stick (or a Hobbit, if you’d rather). And this year, he was Thor. Never once have I considered dressing my boy up as a ghost or a skeleton, and I don’t understand why people keep giving me pumpkin costumes. (This is the first year I haven’t been given one.) Pop culture every year.

So why do we do this? There was a kid—and man, I wish I’d gotten a picture—dressed up as a Sharknado this year. Heck of a costume. Technically, it was very impressive, but you still have to wonder who dresses their nine-year-old up as a Sharknado. Or their one-year-old up as a character from an obscure webcomic.

I’m trying to remember, now, who I used to dress up as when I was a kid. Laura Ingalls Wilder, at least once. The Goddess Athena, once in elementary school. Ziggy Stardust, my senior year in high school. I know my younger sister was a ghost at least once, and that’s about the only “traditional” Halloween costume I remember any of us wearing.

Yet this weekend, I saw a lot of grousing from various people online about how they saw tons of kids wearing the exact same sort of costume I make for my kid every year. (Well, not quite; most of the ones I saw this year were purchased, not made.) Apparently they saw something wrong about dressing up as Captain America or Elsa from Frozen. It’s enough to make me wonder who they dressed up as when they were kids.

The original Halloween costumes, of course, were tied to the holiday’s origins as the day when spirits walked the Earth. So you dressed up as a spirit to confuse them. For protection. And, yes, wearing costumes is fun, and that sense slowly but surely took over. And for nearly a century now, people have been dressing up as pop culture characters.

Maybe it’s because it’s the one time of year when we can be open about our interests, at least in part. Being a geek is better now than it ever has been before, but when I was a kid, it was still okay to dress up as a ninja turtle or Batman, even if it wasn’t necessarily safe to admit caring about ninja turtles or Batman any other time of year.

So okay, that doesn’t necessarily explain the Sharknado kid. And yeah, I put my kid in a homemade Thor costume when he doesn’t even know who Thor is, though of course a costume for someone his age is more about the parent than the kid. Still, though, it’s not exactly as though my fondness for Marvel characters comes as much of a shock.

But I think, in the end, it goes to the same odd sense of familiarity that drives so much else these days. And, in an odd sense, I think it’s about novelty as well. I saw a kid dressed up as a devil, and it was like, okay, that’s a fine costume. But I keep dwelling on the Sharknado kid because it was interesting and novel. Someone took the time to make that; it isn’t something you can buy in stores. I’m even pretty sure I remember it being lit up. That’s an impressive costume even if, like me, you find the movies more tedious than anything else. You’d have to put a lot of work into any ghost costume to make it a truly memorable ghost costume.

This year, I saw about a dozen Captains America. Next year, I probably will again, but there will also doubtless be a lot of Star Wars characters. And whatever other movies come out and catch the public interest. Pop culture costumes have dominated the holiday since the 1930s, and I’m not sure why anyone is showing surprise now.