I remember a number of pieces appearing on the tube when Private Ryan was released in which guys who were there said that Speilberg got it exactly right during that first half hour.
Ryan caught all of that and combined it with the terror and confusion of combat and how you just had to "soldier on." Not heroics, per se, just doing the job. And he'd been a drill instructor at Camp Croft since the lead up to Operation Torch, then on to England for the build up and more training. He had all of the actions down as second nature through all of the drills. It wasn't the same, but you fell back on training, he said, as the only thing you could do.