LET'S MAKE A LIST OF ALL OF SANS'S GODDAMN CAPITAL-I ISSUES WHY DON'T WE

• Some of the most important people in his life - Papyrus, Newt, and Hermann - have all disappeared. He's used to this. He also doesn't know how to handle this in the long-term, and is progressively getting more and more wrecked by the day.
  
• He's gotten very close with Chara, Frisk, and Asriel, despite the fact that all of these kids have actively attempted (and in Chara's case succeeded) to kill him at some point and it feels like an inherent betrayal that he likes all of them.
  
• Alphys and Asgore are here, and he suspects that both arrived off the heels of their own deaths and/or suicides.
  
• Literally everything his double did to everyone. He's got MASSIVE GUILT over that.
  
• His double also handed to Frisk and Chara the keys to their destruction - that is, a binder of studies done by the vanished Dr. W.D. Gaster, which can more or less be used as an instruction manual to wipe them out of existence. He's terrified that they'll succeed in this and that he'll lose yet more people he's grown to care about.
  
• Frustration and guilt over the number of people in this cave he's begun to regard as dangerous - Yukari, Hux, etc. - and his complete lack of motivation to do anything about it.
  
• Generalized self-loathing over being a poorly-motivated sack of trash who does little besides crack horrible jokes and antagonize people
  
• Guilt about his death during the Doubles event and leaving Chara, Frisk, and Wade behind to clean up his mess (almost everyone else in his immediate CR circle was dead lol)
  
• idk and more probably

HE IS NOT GONNA WANT TO TALK ABOUT THIS SHIT. but since i want to wreck this skeleton's stupid ass i'll probably force him to chat about it at some point lol