Or, the end of the mini-ice-age resulted in flooding that equated to a rise of something like 20 stories (as in building levels) of water in lower regions including the Fertile Crescent. It would make sense that the first (known) civilizations would have great flood myths because their lands were wiped out during their lifetimes. Did the entire world flood? From their perspective yes. From that of geologists, no.
Edit: Oh, and I want to cancel all religions. Christianity isn’t special.