Comment by api

A while back it dawned on me that we think the greatest past civilizations were all in Egypt, the Middle East, and Mesopotamia because those areas are deserts or semi-deserts. They built out of stone because they didn't have much wood, and their writings survived because they weren't destroyed by water.

There could have been very sophisticated societies, even large scale civilizations, in the past in places like North America that built mainly out of wood, clay, bone, and other readily available materials, and there'd be nothing left. Any writings would be gone too, since writings don't survive well in wet climates unless they are chiseled into very durable stone or vitrified pottery (and even then they can erode).