He is pretty far out of the loop on all this stuff, so his own interpretations are the only ones he's heard. The notion, I have memories from another life in another universe, there's a few ways of looking at it.

One's that that other universe was a past life or something, something over and done with that could, due to whatever magic's letting those memories persist into this reincarnation, give people the insight not to repeat their old mistakes. Or the baggage to drag them into the same ones.

Memories from a future, impending collision timeline, that's bizarre and unintuitive.

The remaining big option is, what if this whole life is just a simulation, but that's terrible and uncomfortable; not only does it fit way too many crazy person cliches from TV, it leaves all the other people in this life in the lurch as short-lived background NPCs. It might be true, but you don't just say it like that.

Papyrus blinks at the sudden handholding, struck by a sudden familiarity -- and the sense that he's too tall for this recognition to fit right. The angel helpfully lifts into the air as he thinks it, and yeah, there's something about this sight that hits close to the heart. He smiles a little, crooked smile, opens his mouth to ask what brought this on...

Then suddenly they're flying, and somehow his arm isn't being wrenched off.

"Wowie you can move fast, oh my god, we're booking it. How doesn't this hurt?? Where are you taking me?"

Who says 'wowie??'