How true. All of boot camp for me was the annihilation of my pre-Marine personality. Semper Fidelis came to mean always faithful to your fellow Marines and your Corps. I recall once in combat school, we were preparing for a two-day war (combat exercise), and the instructor was telling us about hand illumination grenades (in those days, they were willy peter grenades). "Don't jump on one when it goes off and try and save your buddies from the light, 'cause the thing'll burn a hole right through you and still light up the area" he told us. Everybody laughed, but I think he was serious.

Hell yeah, in a tight unit, you'll do almost anything but let your buddies down.
To outsiders, all that cadence and "Hoo-ah", coin checks and nicknames looks like something arcane or stupid. I served 21 years in the Army, and was fortunate enough to be in a few units where our esprit de corps was the only thing that kept us going, and I feel for anyone who never had that kind of experience.
What a great story. No doubt there's already some schmuck trying to play it down, debunk it, or make fun of it.