A single book changed things.
I bought Walter Lord's Incredible Victory, a journalistic account of the Battle of Midway which interweaves the experiences of multiple participants on both sides. I bought it not from interest in battles but because on its cover was an illustration of aircraft and aircraft carriers: the machines I believed for much of my childhood were the future I would pursue. To my great surprise I learned of strategy: that battles are planned, and decisions are made on the basis of geography and relative strength and how each side's specific capabilities can be maximized while taking advantage of the enemy's weaknesses.
Before then I'd more or less imagined battles were like the Monty Python sketch, "Batley Townswomen's Guild Presents the Battle of Pearl Harbor" — a melee without form or forethought. Now I understood battles as intellectual exercises pitting wit and strategem. It was brains over brawn and I dove in brains first, clearing the Hardy Boys from my bookshelves, replacing them with the entirety of Western military history, from Babylon to Vietnam. Not children's books: books from the military history sections at Borders and the big B. Dalton's in Fashion Valley. The same books adult hobbyists read in their armchairs after dinner.
This was an entirely new identity. Where before I was sports and school avoidance and The Lord of the Rings, now I'm sports and school avoidance and military affairs and The Lord of the Rings, where the books I read at home while malingering from the City Schools were of Rommel and Napoleon and Alexander and Nimitz.
I really had no interest in gore and explosions. I did not engage with the reality that living humans just like me and just like my friends and my mother were grievously injured by the activities which fascinated me. I cared about the timing of the attack and whether or not the Maginot Line had been a good idea.
There was a short list of commanders I greatly admired. Wellington was one. He had his men lay down on the reverse slopes of hills so they could not be counted by the enemy, and so that the French artillery would pass harmlessly overhead. He chose his battlefields, including Waterloo, for that purpose. He'd scouted the Waterloo position a year before the battle.
Yet so was Napoleon. I admired the speed and audacity of his greatest battles: Jena-Auerstedt and Austerlitz. The way he overturned the earlier positional campaigning of the Absolutist era and set out to destroy the enemy army.
I admired Zhukov, Rommel, Hannibal, Grant, Saladin, Kutuzov, Nelson, Geronimo, Guderian, Nimitz, Giap. The leaders who'd taken best advantage of their forces' capabilities. That was the draw. I had no fantasies of personal fame or glory. I cared about the tactics and strategies of leadership, not particularly its consequences or its outcomes.