The reason for all the world’s civilization's having their own Flood story is because all the world’s civilizations came from Shem, Ham and Japheth: sons of Noah and survivors of the flood. Their stories got passed down to generation after generation. Pretty cool when you think about it.

The reason for all the world’s religions having their own Flood story is because all the world’s civilizations came from Shem, Ham and Japheth: sons of Noah and survivors of the flood. Their stories got passed down to generation after generation. Pretty cool when you think about it.