Board Thread:General Discussion/@comment-26006155-20190617222636/@comment-26006155-20190730142828

Why would someone erase Gaster's memory?

Perhaps they wanted to make sure The Darkest Experiment didn't happen, no matter what.

Even if someone did something to Gaster, Gaster had followers. They might try to continue whatever it was he was working on. Especially if it involved dropping the barrier.

Even Asgore might object to someone killing Gaster, and demand an investigation. And the last thing Sans wants is for someone to investigate him, and take off his mask.

So perhaps the only way to stop Gaster's plans for good, was to make sure nobody remembered them?