One common Undertale misconception that really frustrates me is when Sans is portrayed with a strong innate sense for RESETs and alternative timelines. Like, that he remembers the RESET timelines better than the other characters who only have occasional feelings of deja vu or even that he can sense when a timeline is RESET.
And that’s, like, almost the opposite of the actual text of the game. While pretty much every main character can have slightly-different dialogue in a Not-True-RESET, especially if the Player had previously befriended them, based on the idea that they have lingering memories/feelings from before the RESET -
Sans has no real dialogue changes based on this conceit. All of his changes are based around noticing Frisk has different reactions based on their memories of the precious timelines.
Other characters do also make observations like that about Frisk, like Mettaton and Toriel. But Sans is distinctive because this is the only way his comments change between RESETs and there are a lot of them from him.
Because that is what really frustrates me about this misconception. People mention it as one more thing that makes Sans cool - but the actual truth is far more badass. Sans is one of the people in the Underground who remembers RESETs the least. I think memory-resistance to RESETs is probably tied to Determination. Flowey, the second-most Determined person in the Underground after Frisk, can remember everything perfectly.
Everyone else has some vague feelings and deja vus. And Sans, he’s the least motivated person in the Underground - both in the sense he’s lazy and in the sense he’s fucking depressed.
That probably means he has very little Determination. Thus, he doesn’t remember anything that happens between RESETs.
And yet, he is still the character most aware of them. Because he has the technological know-how to read and analyze timelines.
And because he has the observation and analytical skill to notice a RESET from other people’s reactions and behavior. Whatever it’s Papyrus thinking he recognizes someone or Frisk’s behavior implying that they know something they shouldn’t have. Sans main RESET-related skill is just being able to identify these moments and come to the correct conclusion about them. And with that he manages to be the most aware character in the entire Underground.
Like, the one point where it might seem like Sans remembers something from a previous Timeline is the Fake Spare scene during his boss battle.
But it’s all pretend. Unlike the previous lines from other characters that I mentioned, this dialogue plays even if the Murder Route is the first time the player touched the game. Sans isn’t remembering anything in this scene. But he makes an educated guess that the Immoral Time God probably tried using their powers for good at first, so they were likely ‘friends’ in a previous timeline. And in most cases, his guess is right on the money - tricking many players into thinking this is another case of the game actually reacting to their past actions.
And as always, Sans can only tell if his lil’ trick worked or not based on the expression of the Player Character.
Arguably, Sans even uses his lack of Determination and cross-RESET memory to his advantage in his boss battle. After all, the whole point of this fight isn’t to kill the Player - Sans understands this is impossible. This is a war of attrition, trying to get the Player so frustrated and annoyed with the unfair fight that they just ragequit or RESET the Timeline. And this war of the Player’s patience versus Sans’ stamina and will is infinitely easier for him when he doesn’t actually perceive all the Player’s previous attempts against him.
Like, for the Player this might be the billion time they go up against him, they’re aware of some of his patterns and tricks now but they’re probably also frustrated and angry and exhausted. Meanwhile, from Sans’ POV, this is still the first time this is happening. He knows it’s not from the Player’s behavior and Frisk’s expression - but he doesn’t feel it like the Player does.
He doesn’t feel the frustration and repetition of the endless stalemate. So he’s always as fresh as a daisy no matter how rugged the Player is getting.
And that’s part of why Sans is so cool in the first place, like, in general. He’s technically the weakest person in the Underground, lacking in every standard evaluation of power in the setting - no ATK, no DEF, no HP, no DETERMINATION. But he’s darn clever enough to overcome these weaknesses and even use them in ways that make them into strengths, enough to be one of the most dangerous and most aware guys in this whole setting.
Sans can’t remember anything, and that makes him awesome.
