Ptsd can be a very detrimental illness and hard to recognise at first. I agree totally with little woman about triggers, I was sitting with a friend one day a few years go and I fidget a lot, this day in particular i was chewing a lighter, never a good idea I know, but I bit it too hard and it bust making a loud bang, this scared the living day lights out of this friend a man whom iv known forever and never saw him react like this to anything. Later he talked to me adressing a subject he ussually keeps very close to his chest, he was in a bomb many years ago and he said that the sudden bang brought back the terror off that day. It never happened too him before that, but when this incident occured he went asap to see some one to talk through something that obviously still deeply affected him. The point im trying to make in a long winded way is that many people dont show any out ward signs and dont even realise the state of their inner mental health untill its too late. And off course you also have the big boys dont cry mentality going on in the military where blokes in particular would be embarrassed to go and seek help.