I am now convinced that what the army is actually trying to do in basic training is mimic the effects of low-level PTSD. They need to ingrain you with the deep-grooved reflexes to behave in certain ways under pressure, and the easiest way to do that is to burden you with an enormous amount of stress; then, once you’re already weak and tired and afraid, they give you things to do. And even though all you want to do is go home, you know you have to keep going. Something about the trauma makes you retain the instruction more, teaches you how to react on autopilot in a high-stress environment.
