[FFP999]

My theory about the Noah's Ark story is that Noah was a real person, who was a bit more skilled at reading the weather than his neighbors, and predicted a bad rainy season in time to build a boat large enough to save his family and some of his livestock. The rest is just the tale growing in the telling.

[Cthulhu_]

It could be literal survivorship bias too, one guy builds a boat in a flight of fancy, turns out to be correct and is the only survivor of a cataclysmic flood, literally lives to tell the tale.

[FFP999]

Or maybe he just had a boat because he liked to fish or whatnot, and that turned out to be really lucky for him.