My 'theory' is that the climate transition between Ice Age and what we have now was SO catastropic that it caused trauma on the collective unconsciousness of mankind. Myths of 'a better time before (garden of eden)" and "the war of the gods (Ragnorok) and "the global flood (noah's ark) are the stories that were passed down over generations from that time. (it was a VERY difficult time to survive. Lots of siesmic activity due to Isostatic rebound and the sea level rose four hundred feet in a relatively short time. It might have rose VERY quickly at times if there were "melt pulses".

Possibly the "Sea People" were a people uprooted by the flood who became early day vikiings?