Stay Up Late was just a soldier, not a high-ranking officer or important individual in the crystallizer civilization. He only knew the history of the crystallizers from what he learned in the history books.
The history he knew about the crystallizers placed their origins in the sanctuaries.
The crystallizers wished to avoid a war, and so they sought refuge in the sanctuaries. Heaven knew how long it took after that before their civilization developed into what it became.
Many elites wished to leave the sanctuaries and return to the outside. They did succeed in doing this, but they were also destroyed. Something bad happened inside the sanctuaries that resulted in the destruction of their entire civilization. That was what became their recorded history.