there's definitely a lot of history, and technological history we're ignorant of.
stuff like
this.
i was also reading an article in national geographic a while back about a pre-historical battleground discovered in Germany, with a shockingly large number of human remains found. they extrapolated, based on the number of dead & number of artifacts found, that several thousand combatants were involved. they were surprised because they had assumed the logistics needed to coordinate and supply armies of this size didnt exist in prehistoric times.
so we can probably assume that a lot has happened we dont know about. entire empires might have come and gone. without electronic communications and ways to preserve information, much of the knowledge of evidence wouldnt spread beyond a local area & could be easily destroyed.
but of course this is still no reason to engage in wild speculation about ancient aliens, angels, gods, supernatural phenomena, or listen to the rantings of the borderline insane, etc. etc. everything can still be explained by perfectly natural, observable physics, mathematics, chemistry, astronomy, biology & so forth.
