Let me explain why WWI is a perfect example. Photos of European political leaders prior to WWI show them richly attired in elaborate costumes and plumed hats. Europe was still essentially a monarchical domain, immensely rich from trade and colonialism. To a man, their leaders believed that the war would be over in a month. Not one foresaw the deadly impact of machine guns, mass artillery, tanks and airplanes. Instead of a month, WWI lasted, in essence, until 1945. Graveyards all over the world house the remains of hundreds of millions of people killed during the 1914-1945 period, the deadliest die-off since the Black Death in the 14th century. Plumed hats are gone forever. I