Earlier quoted context omitted.
How is a self sufficient society with its own language not a civilization? Maybe you meant to say "We didn't leave much of that civilization"
I mean they didn't have much in the way of writing, architecture, science, or organization. They were thousands of years behind the more advanced civilizations. They had a primitive civilization. There wasn't much left of their civilization 120 years ago (thanks to Europeans) and they didn't leave much behind that endured.
I am disheartened by your comment.