Although they may be considered primitive by today's technological standards, they were very, very smart and accomplished tremendous things with very little resource.

They were not primitive intellectually. They were smart, capable and intelligent people.

This is exactly the point many people don't understand: People in the past were not less intelligent than today's people.

We developed more ways to discover stuff and more precise tools to measure and detect things and of course with computers we got the ability to handle extremely complex data. All of this gives us an edge over past people science wise but we had very capable thinkers 200, 600 and 4000 years ago. All basic principles of mathematics have been developed a long time ago.