The lesson that I hope future generations will have learned
History will record that our unsustainable civilization flared and then collapsed over a period of six thousand years.
It took off after the turn to a form of agriculture that was unecological (clearing the land of all other fauna and flora) and anti-social (private ownership of the land its produce). That led to pernicious wealth accumulation, power elitism, technological development, and statist domination.
I just hope that future generations will look back and comprehend the problematic trajectories and values of the period of our civilization. It created awesome, gigantic, powerful institutions and technologies. But those things don’t make people happy.