Well, I guess I don't know how much I remember, compared to how much I forgot. [Sans joins Papyrus on the grass, though it's more of a drop than a settling.] Maybe that's just semantics, or-- [Sans reaches up to scratch at the back of his skull. This is a whole set of dominoes he's nudging at.] Okay, so. His name was Wingdings Gaster. He was the Royal Scientist before Alphys.

[Those memories are very solid, now. His most concrete memory is of how their dad died; now it's easy to remember the circumstances of it.

He guesses that means their family name is Gaster? That's not the most important fact, but it probably makes more sense than "the Skeleton".]