But what about the millennia beyond the current 2 millennia or so of human experience and understanding of which you speak?
Cultures all over the world believed the Earth was flat for quite a long period of time.
And if you say "we're smarter than they were" then why can't we figure out how they built the pyramids, the antikythera mechanism or any number of other things.
Our time is but a shadow of the past.
Ancient people believed in lots of things we now know to be myth. They were at the beginning of this culture's learning curve, and gained an understanding of the mechanics of the physical universe one inch at a time.
It's true that there are still mysteries yet to be solved, but the basic composition and configuration of planets isn't one of them.