Last week, I started watching Attack On Titan about 13 weeks after everybody else got into it. Finally, all the memes on my Tumblr dashboard started to make sense!

Things were crystal clear for a hot second, up until Free! began airing last week. Overnight, posts about Titans were replaced by posts about swimming. It’s the circle of fandom, the rise and fall of our obsessions within obsessions.

Attack on Titan and Free! both just happen to have large female fan bases, making the switch that much more sudden and apparent. But usually, we’re only marginally aware of the drift of fandom. A feeling in the back of our minds like, “Weren’t bronies a big deal in just a few months ago?” or “Has it really been a year since I last played Skyrim?”

What makes fandom drift interesting to me is that it mimics newsgathering. Some scholars describe our news cycle as a spotlight, highlighting one thing for a brief time before moving onto the next. It’s why you’re not still hearing updates about victims of the Boston bombings. It’s why the front page changes overnight, or every hour online.

The thing about identifying as a geek, nerd, or otaku is that we tend to have a lot of interests under the same umbrella. We’re always looking for the Next New Thing, then the thing after that, and then nostalgia for the first thing, making it new again.

What’s more unusual is sticking with one fandom for long past its air date. It tickles me how my friend and colleague, Aja Romano, is still participating in a fandom for two side characters in Inception, a movie that is now three years old. My husband, too, prefers to keep his fandom in the 20th century, re-watching Patlabor and Star Wars. It took a lot of convincing to get him to try Attack on Titan.

But refusing to keep up with fandom drift results in more social consequences than failing to keep up with the news. If you can tell me about the unrest that’s going on in Egypt right now, you’re in the informed minority. But if you don’t want to know that Snape kills Dumbledore (and I’m keeping my example dated on purpose), you can’t even sign on to Twitter or Tumblr without being spoiled. Plus, as XKCD once pointed out, by the time you do catch on, your friends will find you infuriating.

When you join a fandom, you become part of an obsessive, intimate—and temporary—community. If you get in at the onset, you’re getting the best possible fandom experience. You get to talk with big name fans before they become special guests at conventions, participate in the creation of the fandom’s first memes and fan works, and enjoy being on the inside just as everyone else is starting to catch on.

But if you get into it late, like I did with Attack on Titan, you’ll just be browsing a digital ghost town that’s left behind in a swimming anime’s wake.