T-Rex: If rain wasn't a thing that regularly happened in most places of the world, and then one day it did, we would all FREAK OUT!! We'd be all "AHH THE AIR IS WET SOMEHOW, AHHHH"

T-Rex: "IT'S NOW TECHNICALLY POSSIBLE TO DROWN ON LAND; AGAIN: AHHHHHHHH!!!"

T-Rex: But since it happens regularly we're all "oh cool this is normal, definitely a normal thing to happen on a normal planet". And if we never sneezed and then one day started sneezing, it'd be the same thing: we'd FREAK THE HECK OUT. Imagine being the first person to DREAM?? You'd think you were either crazy or teleported!!

Utahraptor: Ah, this is the black swan problem! We can't predict unpredicable things.
T-Rex: Explain!

Utahraptor: In Roman times they'd say "rare as a black swan", because as far as they knew black swans didn't exist. But then in 1697 Europeans saw some in Australia and were like "aw geez, this idiom needs some updating" and now it's used for things you can't predict, like rain on a planet where it had never fallen before!

Off panel: And that's comforting, isn't it? Some events will always be unpredictable, simply because not everything that CAN happen HAS happened.
T-Rex: BERAHFUSAH!!
T-Rex: ...is the sound of me VERY helpfully narrowing down the ol' "hasn't been said yet" list