Board Thread:General Discussion/@comment-34404946-20180120072411/@comment-27136653-20180203225055

Your post didn't really introduce any new arguments. You simply said that there's no reason for Sans to have 1 HP from an in-game point of view.

But actually, I'd like to expand on that a bit. There is some "technical" proof that Sans's HP should be higher than 1, even if 1 is his maximum.

You see, it is a common knowledge among the monsters that sleeping can raise your HP above the maximum: https://drive.google.com/file/d/0B6gS2LPXdIc5d2VrOGpZdzExeTA/view

This could just be unique to humans, but the thing is, most monsters don't recognize you as a human. So assuming that this bunny family doesn't either, that little bunny must have been talking about a monster characteristic then, which would prove that this is a feat of monster souls too. And I believe that this is the case, since usually when someone recognizes you as a human, they say it out loud. And I don't think there has ever been an instance of a monster recognizing you as a human and not telling you about it (maybe Alphys, but one would assume that she knew, since she's the royal scientist; we're rather looking for cases where we aren't sure whether a monster would know - so literally everyone except for the high-ranking monsters).

Anyways, I take this as a pretty conclusive proof that when a monster sleeps, their HP recovers above their maximum value. Which would in turn explain why Sans is napping so much all the time. Maybe he's very well aware of the fact that his max HP is literally just a single hitpoint, so he's trying to nap as often as possible to sustain as high HP value for himself as possible.

And why? Well, who knows. We don't know a great deal about him or his past life. But he does seem proficient at dealing pain to humans, so maybe he had some prior experience with that. Maybe he's aware of the danger the humans possess, which is why he's doing this.