Ah. There's a note of sympathy in Sans' face, for all it's hard to see through the vacant sockets and permanently fixed grin. Leaving your world behind was difficult for some, even if Sans couldn't specifically relate. There was nothing left for him back there.

"Heh, well, if nothing else, this place is pretty friendly. ... Y'know, horrible planetary escapes aside." Wink. "Bar's pretty chill. I hear you can find skeletons there some nights, not that I'd know."