Note: sociologists from thousands of cultures have speculated for thousands of years about the origins of the prevalent (but largely unsupported) belief that "the ancients" knew something we didn't. In some Earth societies the belief could be tracked to an actual fact that the ancients did have something going for them, but those societies were in the grip of the "dark ages" and were living in the actual shadows of Roman Aqueducts, so they had a pretty good excuse.
Their descendents 800 years later did not.
SORLIE: People have been suckering each other with "secrets of the ancients" scams for thousands of years.
Claiming that some lost technology has been re-discovered is pretty much the same as saying "I am running a con."
ENNESBY: So you see our problem.
SORLIE: Of course I... No, wait. Your problem?
ENNESBY: We want to sell actual re-discovered technology, but our potential customers all think they're too smart to buy it.