[Palm Springs] The characters aren't just stuck in a time loop. They're stuck in a time loop WITHIN a time loop.

At the end of the movie, Sarah figures out quantum mechanics and how to beat the time loop: by blowing up the cave at the right moment in the glowy thing and freeing herself. Before leaving, she tells Nyles and calls Roy. She and Nyles leave together but Roy stays behind.

So Roy heads to the wedding and meets with Nyles, only to discover Nyles doesn't know who he is and seems confused.

This leads to a host of questions. What happened to Roy in the world where Nyles and Sarah escape? Of Roy gets out, will he meet the current version of Nyles and Sarah or another? These are all legit questions, but they're existential. Really, the question is:

How did Nyles find the cave in the first place? Hear me out:

Roy would obviously go to the cave and blow himself up. Perhaps Nyles, in curiosity, follows Roy and enters the cave, thus starting the loop. But since Roy escapes, Nyles is the only one who remembers. Then he brings in Roy, then Sarah, then Sarah figures out how to escape and she and Nyles leave together. Roy arrives and the whole thing starts again.

Of course Nyles doesn't remember because it's been ages since he started the whole thing, to the point he doesn't remember his life prior. There's a stable time loop containing this time loop.

TL;DR The time loop is caused by a time loop and I have a headache.

Note: Sarah enters the cave and the glow after Roy and Nyles, meaning that the pocket they leave continues even after their sleep/death/disappearance. This means that there are millions of threads of this universe existing where the characters likely disappeared. This didn't fit into the overall theory but I thought I'd say something.