Casual fans accept that Disney movies take place once upon a time, in a land far, far away. But Tumblr users are not casual fans. And they want it all to mean something.

Welcome to the esoteric and frankly mind-boggling world of Disney fan theories, which posits that all of Disney’s animated movies take place in the same universe and characters from different films interact in ways you have to squint to see. Andy’s mom in “Toy Story” is actually the cowgirl-doll Jessie’s original owner. Belle, from “Beauty and the Beast,” secretly loved Aladdin.

The latest fan theory rocking this small but vocal corner of the Internet involves “Frozen” and 1989’s “The Little Mermaid”: What if, fans argue, the sunken ship Ariel explored 24 years ago ... was actually the ship where Anna and Elsa’s parents perished in “Frozen”?

The evidence for this theory is, of course, scarce, despite the amazing effort that some people have pumped into researching it. Still, the idea isn’t so crazy when you consider Disney’s penchant for dropping similar Easter eggs over the years. Dogs from “Lady & the Tramp” surface in “101 Dalmatians.” In “Aladdin,” the sultan stacks a series of model animals that include the beast, from “Beauty and the Beast.”

Conclusive proof, fans argue.

What that universe would look like, it’s hard to say. It would have to include places as far removed as modern-day Australia and magical medieval kingdoms. (Which has led to another unified theory of Disney movies: They take place in the same universe, but non-chronologically, along a time line that spans millions of years.) Further complicating things: Some Disney movies are explicitly tied to real geographic locations, while others are not. Just try pointing to Atlantis on a map.

This vastness hasn’t stopped fans from trying to plot the Disney universe. Twenty-six-year-old Eowyn Smith’s recent map, which she posted with extensive citations on Deviantart, racked up thousands of comments and dozens of media mentions within days. Smith told the Huffington Post that she rewatched all of the Disney movies, noting wildlife, backgrounds and landscapes, in order to make the map.

All this raises an obvious question: Why? Aren’t Disney movies enough as self-contained little pieces of art? Do we have to seek out further meaning? With their clue-sifting and screen-shotting and arcanely labeled diagrams, die-hard Disney theorists share something with their zanier, more paranoid cousins in the conspiracy world: a belief that some greater power is orchestrating everything, and they are the only ones in on the plot.

Of course, there’s a big gap between blogging about the New World Order’s political machinations and Disney’s creative ones. The latter is, obviously, more fun. That said, it’s pretty absurd to think some god-like creative at Disney is lurking in the wings, anonymously plotting the interacting story arcs of hundreds of films and characters.

Then again, if the Tumblr hordes have time for that, why wouldn’t Disney?