On the delusional side of things...
StarGates : are an interesting concept..
people have different views about ancient structures..
reinforcing the belief or common sense that something superior walked the earth before..
and something that 'evolved' : left clues and literature : for next species to follow..
But : we live in oil$ world : where space acrobatics are preferred than solving for 'energy'.
further thoughts...
few interesting movies on the concept :
imdb.com/title/tt0942903/i believe in 'many histories' version of 'history' - not 2K years of it.
many histories happened : many religions : many reboots.
the preached history : is convenience of thout and intents : usually by people who print it.