Some cultures (US, in my personal experience) spend quite a bit of time convincing themselves that terrible things can't happen to them. For instance, I could be hit by a bus tomorrow in a freak accident and suffer a more painful end than a soldier in Iraq. That's not to say that Iraq isn't much more dangerous, but danger exists for everyone.
I feel for the soldier you're replying to because he is at odds with society in this regard. However, he's not at odds with reality because bad shit really does happen and I admire his not being so quick to label it some kind of illness.