THIS is Why The Sumerians are NOT Taught in School - Sumerian Tablets - Lost Ancient Civilization
I am not too concerned about why Sumeria is given short shrift in schools. The powers-that-be have their own agenda and unless you have your own army, fighting that is going to be a losing battle. I am a little curious about history and I do wonder if there might have been an advanced civilization before the last ice age glaciated a large part of the Northern hemisphere.
We've been watching Ertugrul, which is set in the same area about a thousand years ago. The story is that nomadic tribes have been living the same type of life for hundreds, if not thousands, or years. They have traditions, which are basically rules for living that have been proven to be beneficial to the survival of the tribe. Some of their rules might seem foolish or even stupid in the glare of modern life, but you can bet there were very good reasons for those things back then. You just have to adjust your thinking to compensate for the situation.