In Re:ZERO -Starting Life in Another World, Subaru's Memory Loss Was Intentional, Not A Glitch
The Theory: In Episodes 10-11, Subaru loses his memories and Ram goes off on him for "forgetting Rem". Everyone treats it like a random side effect.
But fans think it's the Watchtower itself erasing him.
The Conspiracy angle: The tower is called "Pleiades" — 7 stars. Each floor could correspond to a sin, a witch, or a memory. To ascend, you have to "shed" parts of yourself. Subaru losing his memories of Rem specifically hurts because he "vouched for Rem" and "said he'd take responsibility".
Some fans think the tower is trying to make Subaru forget his attachments so he'll become like Flügel: detached, logical, willing to sacrifice. That's why Shaula calls him "master" — she's seen this version of him before.
The scary part? If he loses enough memories, he stops triggering Return by Death the same way. No attachments = no reason to come back. The tower could be farming a "perfect" Subaru.