Define advanced technology.
There is a lot of advanced technology ancient peoples had that were lost.
Batteries, Germ Theory, Eye surgery.
Greeks had all kinds of weird mechanical steam toys. Heron's theatre and all that.
Or that one doctor in Chinese history/myth that knew about cancer during the "Romance of the Three Kingdoms" era.
Ended up killed by Cao Cao, forget his name right now... Hua Tuo?
People were a lot smarter and more advanced back then, then we give credit.
Hell people think ancienet people generally thought the earth was flat... when anyone who lived near a body of water no doubt knew otherwise, watching someone sail over the horizen.








