Quite possibly nothing. Stress can alter your brain if you’ve experienced long periods of it. The effect is that the gap between a thought and high anxiety is quickly crossed, and reason is much less able to bring good sense to the situation. This idea has been around for some time, but it’s been receiving more confirmation recently. See also this.
Though I can’t speak to the utility of such brain changes in battles, many of us who experienced ‘very difficult’ childhoods know it can be extremely important to detect early signs of adult induced doom, so you get advance notice that can send you in a ‘battle preparedness’ state. Recently on NPR the author Pat Conroy described the utility of such early warning. When his military father was going into a rage, Pat’s job was to get the children into hiding.
So suppose you survive but can get hyper anxious. Many young women do not want to get pregnant, but if you are extra worried, a therapist may well tell you that it shows you really want to get pregnant. Very worried you could fail as a parent? That shows you want to harm your child.
Little by little someone who can’t dampen down basic fears is taught that really her anxiety is due to her being out of touch with her real fears.
There are reasons to be worried that much in our culture permits the psychiatric assumption that others are more opaque to themselves than they are to us. I think we should stop thinking that way!