Social memory, or the lack thereof
I've been thinking about this with the volcano in the Canary Islands.
We know that there is always the undercurrent, a mantle plume, of the Fascism way. It's always there, trying to bubble up, and wipe out progress. Every eruption is different, but they are also the same.
It only takes a generation or two to forget the last time the volcano blew.
(updated)