Back at home, you'd run into the problem that you could glue together the bits, but you'd burn out yourself to the point where your heart couldn't take it.
The analogy they gave us was like grief. You can tell someone to get mad about it, or talk it out, or try and distract themselves, but the weight - that weight takes time. Trying to force it doesn't help.
Admittedly, the army's solution was to tell people that nightmares meant you were finally healing, since your brain had decided that something horrible was horrible. Which - sounds kind of terrible to me, looking back at it.