A century is 100 years. Some people say that a single year contains 365 days, but this isn’t actually true. One hundred years may not sound like much on its own, but it’s an eternity when you consider the length of time in which humans have existed and evolved. This article has been about how long we’ve walked the earth for as human beings so far, and what to expect from our species moving forward into the future. Hopefully these tidbits will help make sense of some confusing measurements used by geography teachers or math professors!