Well said, Caroline.
'Blood shock' was a term given to Finnish troops in their winter war with the Russians before War II in which some of the Finns had killed so many Russians that they could no longer fire at them and had to be pulled off the line. I can see the point and correlation. Combat changes you and it really isn't something that can be talked about with anyone unless that person too has experienced it, even for a short time.
Wellington's melancholy comment about battles lost and won is more truthful than most of what else has been written.