The way I look at it, there have been many lost cities of Atlantis, many Noahs and many Gilgamesh over time. I'm pretty sure that as the world warmed at the beginning of the Holocene and the last remaining glaciers disappeared, many human coastal settlements were lost, some of them relatively advanced for their time. It can happen very fast. For example, if the arctic sea ice did disappear at the beginning of the Holocene, then temperatures would have shot up quite a bit melting glaciers at a much faster rate than today. I Imagine that water vapor would have increased too. That could have caused great floods that no human alive has ever seen. Also a high tide after a year with particularly fast glacier melt, could completely submerge vulnerable ancient coastal civilizations.
These events stayed on the collective memory of humanity in the form of Atlantis, Noah and Gilgamesh. I don't think we will see these events at the scale of early Holocene simply because there is much less ice today that there was then.