All Quiet on the Western Front

What profound effects are left on the human mind when, at just 20 years of age, all a person knows is gratuitous, senseless violence that only leads to death and despair? How does a person watch his only friends from school get killed, shiver in fear waiting and wondering when his next meal will come, and survive a multitude of artillery shell bombardments that leave young boys’ body parts dangling from trees and then come back home and pretend to forget everything he’s just been through?