In Brittany, the story is about the city of Ys, ruled by King Gradlon, which was protected by a complex series of sea defences that required gates to be opened at low tide to allow excess water to drain off the land. One day, the king’s daughter, Dahut, possessed by a demon, opened these gates at high tide, allowing the ocean to flood the city, and led to the abandonment of the city.
They also mention Austalian stories, which I commented on before. I don't know if there's a selection bias in what gets reported, but imagine which would be remembered longer--a log of where the highest tide had been for the recorder's grandfather, for his father, and for him--or a story of Ngurunderi chasing his wives?
Some colleagues have expressed annoyance at dramatizations of famous discoveries/discoverers, in which ahistorical conflicts or love interests were introduced. Tell the straight story--and see which one people remember. I'll bet it's the story with the demon-possessed princess.
The calculations change when you have contemporaries writing matters down, but there's still a bias towards "story."