"Yeah?" Based on the conversation he had with Papyrus, it sounds like 'a whole thing' is certainly one way of describing the situation. As far as he's concerned, it only makes the theory that it's a curse that much more plausible. For now, though, he elects not to say as much out loud, musing on what he's just learned instead.

"Sounds like a human would have to try pretty hard to end up underground, then. Not surprising they'd get killed, if humans were the reason you all ended up there to begin with." He pauses. "So why doesn't it seem like you hate humans?"