[Jeebus]

this follows along with Da vinci's inventions as well as many of the ideas of the ancient Greek Scholars and others. They had the write idea on how to do things (like fly) but did not have the necessary materials to make it happen.

I actually (to a degree) subscribe to the idea that there may have been a degree of influence placed on human development by an outside source (like aliens). I see the two main examples being the shift between Neanderthals and [censored] Sapians as well as the almost overnight (historically speaking) growth of advanced civilizations from purely nomadic peoples. Think the things that happened in the fertile crescent or on the Ganges, etc.
I've read a few things on this years ago, the idea can be well supported if you assume descriptions of Gods and Crazy Miraculous things are actually attempts to explain modern things such as airplanes based on an absolute lack of experience in the technology. Think of the effect a team of missionaries has on a tribe living in the heart of the amazon. they arrive by helicopter (big flying bird) dressed in synthetics instead of furs and carrying medicine (miraculous healing). Looking at architecture and artwork can also help to affirm this idea.