Hoping curiousity doesn't kill this cat

Busy, busy day, so I won't be blogging until this evening (assuming I'm not too tired). However, I'd like to use this quiet blogging day to pose a question. First, some background. Phibian, at CDR Salamander, did a post reviewing the new show, Over There (which he doesn't like very much). One paragraph in particular grabbed me:

They need some new advisors with military experience. The scene where they hit a mine is 180 deg out of phase with what I have seen following bloody causalities. People are not wandering around in a mental manic. Just the opposite.

I followed up on this in a comment to the post (I'd always bought into the Hollywood cliche that people are dazed), and Phibian came back and explained that, in fact, training kicks in after something bad happens, and people function very efficiently. Thinking about Phibian's post and the comments got me wondering about a slightly different subject: how and why soldiers are able to make themselves go into battle. That is, how is it that, when all the self-preservation elements of the brain should be screaming stop, soldiers march forward? Is it really all training that keeps people moving forward when instinct (or at least my instinct) would be telling them to run like hell, in the other direction? During WWII, my Dad was in major battles all over North Africa and Southern Europe, but this was not a question I ever asked him. He always pitched his battle stories as adventures or humorous stories, but he would not delve in the pyschology of what makes a soldier go forward (at Omaha Beach, at the Battle of the Bulge, at Iwo Jima, at Fallujah, at El Alamein, at any battle). If you've had battle experience, and are comfortable commenting about this, I'm genuinely curious and would very much like to hear what you have to say. UPDATE: I don't know how I did it, but I managed to post this twice. I'm going to delete the duplicate post, but I want to save Patrick's comment, so here it is:

I have not had battle experience, but I've grown up around the military, and based on books like Leon Uris's "Battle Cry" and Steven Pressfield's "Gates of Fire," my guess is that when faced with combat, instinct says "run like hell in the other direction," training says "the way out might be forward, as counterintuitive as that sounds," and regard for those on your right and left in the same mortal danger says, "charge!" Infantrymen in particular may have signed up for service for the sake of their country, but they fight for each other. That's why elite units, like the Marine Corps and the special forces, place such a premium on esprit de corps and "leave no man behind."