WWII Military Training Films Had No Chill
You'll see that even as we've evolved to this current modern point in the history of humans, things are still the same. Here's a solid ten minutes of time-waster teaching you that you shouldn't settle for a knife when the mood calls for bullets, and you shouldn't trust a Nazi, ever! Preparing a generation of American's for the biggest war the world has ever experienced really took things down to just the basics. Pull the trigger first, figure it out later. Don't feel bad for getting the jump on your opponent. Fighting dirty is fighting to win.
There is a massive playlist of these on YouTube, if you have a few hours of boredom to fill, hit play. It's wild how straight forward training was back then.