“Once I was blown up in a Humvee in Afghanistan and avoided injury because the bomb went off under the engine block instead of the crew compartment—a difference of about ten feet. I was jacked with adrenaline for the next few hours and then went careening into a depression that lasted days. I became paranoid about almost everything: where I sat, where I walked, what I sat behind. It was the ten feet that got me—the fact that “so much could be determined by so little,”