As an ex-soldier, I know full well that most soldiers are pants on head retarded. There isn't a real requirement for them to be intelligent, as intelligence (not to be confused with military intelligence) is something that, if a person has, they tend to use it on things like, not joining the marines as that is a good way to get yourself disabled for life because you are a person who spent most of your life with your face in a book and not on a playing field or doing any sort of exercise, or picking jobs that see them behind a desk, in a lab, or in a shop for repairing vehicles.
I was the smart guy who did the stupid thing, I knew it was stupid but operating a tank looked SOO awesome, and it was, but dealing with tools all day is VERY frustrating and also very stressful.