I'll let you in on another secret. People in the military are in two groups - those who have been shot at, and those who have not. Getting shot at changes your perspective forever, and people who write military fiction but have never been shot at don't really get how it works.

For example, B-17 crews were trained very well, the best that the military could do. They'd have to fly 30 some missions. The probability of dying on the first 5 missions was the same as the probability of dying in the following 25 missions.