There is a lot of basic scientific knowledge that many/most modern people have (germ theory of disease, how the body works at some level, astronomy 101, etc.) But ancient people weren't stupid. They just didn't have advanced technology. Recreating a whole chain of technology to bring about the iron age maybe 1000 years early probably isn't happening. The fact is that they're mostly doing pretty well with building things that the technology more or less exists for.