The ancient world really did rely heavily on exchange of knowledge. Very few people travelled and fewer still had the ability to effectively pass on knowledge. You can actually very easily correlate the technological and general knowledge level of populations to their proximity to major trade routes. It also shows when populations which were isolated how much their growth and development differed, but it also makes their own discoveries that much more impressive. For example the Polynesian peoples who travelled the pacific may seem primitive even compared to their contemporary civilisations, and especially as time moved on that they didn't progress at the same rate. However when you think about the fact that they lived on small islands with limited resources, and all they developed they did so in isolation, their feats are remarkable, especially in navigation and shipbuilding. They sailed the open ocean, and the Pacific at that which is a very challenging ocean to sail, and managed to find tiny islands in its vast expanse to colonise, something that would have been a challenge to many other great maritime civilisations for centuries to come. To this day most sailing vessels use construction techniques those people originally came up with.