I teach an online graduate class in technology's impacts on society. Most students come into the class with the assumption that technology started some time in the early 1900's as electricity became widely available. People lose sight of earlier versions of technology (WWII aircraft are an example) very quickly. They overlook levers, aqueducts, the wheel, steam power, etc. Technology dates back as far as clothing, fire, and the concept of planting food to create a steady, predictable food supply...but it's overlooked.