Well symbols and such have meanings behind them, history shows a bunch of figures plastering them all over the place (one example being Hitler and the swastika (whirlwind of power or some crap like that); King Solomon has used symbols all over the place and such too; claimed to have made several himself), and we couldn't have just been here for just 6 millennia. It just seems so, well, short.
Firstly, symbols are just things that stand for other things. They're just placeholders, in the same way that "U.S.A." is a placeholder for "The United States of America". There's nothing extraordinary or supernatural about that. Hitler's use of the swastika (originally an ancient symbol associated with well-being) changed the association for the western world, but it wasn't
magical. It's just an equilateral cross with right-angle arms. And what does any of that have to do with the length of time humans have existed?
Considering mankind's behaviors with great powers, I think it's a pretty rational reason to lock such capabilities, and obscure it into oblivion to ensure the safety of mankind and rebuild after some heavy destruction. Some jackass must've summoned a meteor to end everything. Plus, we can't let secret societies get off the hook with their odd behaviors. Who knows? They might be spending eons trying to unlock their potential. Some may have achieved it, and are just dicking with us with what power they have found.
I was asking for a rational explanation of why you think such "powers" ever existed at all, not why somebody would hide them.