[Terrans are remarkably good at the mental leap of logic required to justify that only the recent past means anything and that ancient history is utterly worthless information.

Yes, logically, there is a progression of information. But it's so much easier to think of information as belonging only to their world, their enlightened sensibilities...]

... I-Information before a... c-certain period was, er, e-essentially completely disregarded...

... Only recent s-scientific and technological advances were, er, c-considered to have... value.