Based on a true story?

As has been mentioned here, the story of a "Great Flood" is told in many ancient cultures. Evidence for the sources of these stories has been presented, but no one knows for sure why these stories took root.

Geologic catastrophe or divine intervention, take your pick. 

https://www.google.com/#q=sources+for+the+Great+Flood

"I’ve had a perfectly wonderful evening. But this wasn’t it." - Groucho Marx

There are no stories in the Holy Babble that are "true stories". It's all fantasy, fairy tales, fables and outright lies.

I spend my money on dope, sex and cheap thrills.
The rest of it, I waste.