There were several sea rise pulses during that period where the sea level role by about 1 metre per 20 years for well over a century. Given that it wasn’t unknown for adult Neolithic people to live into their 60s or even 70s, the elders in a group would likely have seen around 3 metres of sea level rise on their lifetimes. Also sudden catastrophic flood events must have occurred during a period of such massive change, especially given human populations generally are concentrated near rivers and the coast.
It answers the questions, "Where could the water for a worldwide flood come from? And, where could it go, afterward?". A: The water came from melting glaciers, and it's all still there, drowning the ancestral homelands.
Australian oral traditions record social upheavals when people moving out of the flooded Sahul region (between present Australia and New Guinea) had to negotiate shared use of the high ground that had already been populated for at least 40,000 y. It seems a safe guess that it would be traumatic to have to leave an area your people have lived in for tens of millennia.
