is it because they didn't know how to write? even if they did , is there any other reasons ?
History was often passed down orally. Also, modern paper does not actually last that long and ancient paper (papyrus) didn't last long at all. I would assume a lot of history was lost this way. For instance, The Odyssey, The Iliad, The Aenid, Dante's Divine Trilogy, and other works of literature such as these refer to several texts that we know existed, but they were lost. The Odyssey was memorized and then transcribed by many different people. We know the story was transcribed correctly in the was it was originally told, because we have many different copies of it from many different places. Other documents that were perhaps not seen to be as important were most likely not written down and re-written down and, thus, they were lost. I think that there is a good chance a lot of history was lost this way. Also, history was "erased" often enough by the winning side after a war. Often, documents were ordered to be destroyed, and this could account for the loss of history as well. There is no objective answer, but as for speculations, there are many. It's hard to give a concrete answer for something such as this.
You are correct. I was over-reliant on a documentary I watched some time ago, where they may have said 35 centuries, and I guess I misinterpreted it as 35 millennia. Thanks for the correction, and apologies for my misinformation.
A lot of ancient cultures had oral history that was passed down through story telling. And like they said above, some cultures did write their stories down
That's like you writin' about your own life... I guess they had nothin' important to write about. They had an normal lives I guess.
35,000 years old? The earliest cuneiform writing was from around 3,000 BCE making them about 5,000 years old, not 35,000.