Probably polar shift happens more often than we think. Scientific records really don't go back that far. Before that it's just all campfire story-telling time.
One story scares the piss out of everyone though, the Great Flood.
There is a reason our Secret Society esoteric cult buddies keep building is under The MILE High City in Denver, and extensive tunneling in the Gotthard Tunnel high in the Swiss Alps…not enough room for everyone, so you're in Water World.
Polar Shift. The Great Flood. Water sloshes over the whole earth when she keels over. Think people built fake mountains (pyramids) for giggles?
All cultures have two cultural things in common: 1) How they describe ghosts around Halloween; and 2) Great Floods. Japanese Kami stir the ocean, two Japanese to repopulate. Norse Gods, Odin dies, two left. Bible, Adam and Eve. Mayans. North American Indian mounds. Babylonians. Cambodians. Indians. Everywhere.