Take my best friend for example - we went to the exact same places in the Army - same place for basic, same place/company for AIT, same company in Korea, same company in AZ, same platoon in Iraq - drove the exact same convoys/pulled the exact same duties, back to the same company in AZ - he has PTSD. I do not. Why? We saw/did/got shot at exactly the same. What is the difference? No f'ing clue.
It makes it hard when I talk to him and when I read things here and elsewhere because it just doesn't fit in my brain. People deal with f*cked up sh*t and do not have mental illnesses/disorders. What makes them different? It is too easy to say "He/She is just making that up." Of course, no one would say that about cancer or some physical illness so why do it about mental illness? Perhaps we are just assholes. I don't know.
Anyway, TL;DR - mental illnesses make no freaking sense. They are hard to relate to. It is not Hulky's fault.
Edit: it is obviously not your fault either. I do not mean to imply that. It is just not something easy for those outside of the situation to understand.
Edit 2: I think another part of it is the supplementation. I have 'Restless Leg Syndrome' I have medication for it. Since I went primal and fixed my diet (mainly a magnesium deficiency) it has basically gone way down in frequency. So in my mind I do not have an illness. I had f*cked up eating habits. If mental illness can be fixed by an herb, an ammino acid or eating liver (or wtf ever) is it an illness or poor eating habits? Again, it complicates the issue. And, again, I do not mean to trivialize it. I am just trying to wrap my head around the issue.