With the abundance of the Great Flood myths across many cultures, I think its fair to assume that these culture went through some type of flood.
We do have scientific evidence of that.
Yes, people make up stories to explain why terrible things happen to otherwise average people and not to this other near identical group of average people. They usually involve the group of people licking the wrong nipple on Wednesday night or whatever the current social taboo is and angering the mighty all powerful being who seeks vengeance through water, because that's just how powerful being's roll.
The problem arises when people equate things like floods, which are essentially guaranteed to happen given sufficient time, and creation myths, etc.
But yes, it's fascinating that all cultures share certain myths. For about 15 minutes. True story: When I was a kid, Joseph Campbell threw me out of a lecture he was giving at Columbia. I've got your hero with many faces right here, *******. Hey, Joe, who's laughing now, corpse? The 'Roo, Joe, that's who. Hahahahahaha man I can't wait to go **** on his grave.
____________________________
Disclaimer:
To make a long story short, I don't take any responsibility for anything I post here. It's not news, it's not truth, it's not serious. It's parody. It's satire. It's bitter. It's angsty. Your mother's a *****. You like to jack off dogs. That's right, you heard me. You like to grab that dog by the bone and rub it like a ski pole. Your dad? Gay. Your priest? Straight. **** off and let me post. It's not true, it's all in good fun. Now go away.