I think it's tied to a strong impression. [Monsters and their emotional weaknesses.] When you meet someone who was a friend once, or--someone who wasn't. [Someone who really wasn't. He knows Toriel has mentioned feeling as if she knew the human children before she met them. He's heard all sorts of things people have said about Frisk. As for him...] I mostly just--notice. When someone's expression is wrong, or when they expect something they don't. Not as much of that deja vu stuff as everyone else.

[Not none, but Sans's emotions are pretty wrecked, and that's no secret.]

But I've got the readouts. The reports. I know to look for it. Never told anyone, unless I forgot about it. Guess I could've forgot about it.