World War I often gets overshadowed by World War II in the history books, which makes sense because WWII scarred our planet forever, but WWI and its aftermath was a terrible and awful moment in history that helped shaped the rest of the century (and beyond) as well. If you forgot about some stuff that happened or didn’t pay attention when you were a self-centered high school student, just watch this really smart animation by John D. Ruddy and Manny Man. It teaches you more about WWI than history class ever did.