As a followon question, in the movie not only were the 18 year-olds excited to join in 1917, but the Headmaster of the (presumably) Gymnasium gave a rousing, patriotic, "we'll be in Paris in a few weeks and I'll see almost all of you back after that" speech to the kids as well. He would probably have given the same speech in 1914-16. It must have been brutal as educators to see your students go off, year after year, with so many coming back maimed or in coffins, and then have to send the next class off.

Is there any documentary evidence of war weariness or burnout in the German educational system?