[discostu]

I think we were too busy. From what we do know of life before recorded history it really sucked and was oriented towards subsistence survival. Not much to record: "bad hunt today, children starve. Good hunt today, less children starve". It wasn't until we started pushing the technological envelope and actually managed to invent liesure time that people started writing stuff down. Of course the birth of beauracracy also has a lot to do with it, that's why we know so much about Rome and so little about colinear societies, Rome wrote down everything.

[RightWhale]

There are indications that towns and maybe small cities existed at the end of the last Ice Age. These were all located in coastal areas that suddenly got flooded out at various times roughtly 10,000 years ago. Who is to say how long these villages and town existed before they were washed away? Maybe a long time. That is where records would have been kept; a lone tribe in the forest wouldn't do well in the permanent record-keeping department.