I never heard anyone refer to it as bringing the shield down. Perhaps because I was Army. I've been out for six years now and I suppose the shield I carried is still somewhat up. My wife always makes references to PTSD and I've always denied them. Like you, I always tell people that nothing very traumatic ever happened to me; and like you, as I say this, certain images do spring to life in my head. However, there are certain indicators that can't be denied. After six years, I still sleep fully clothed and with a sidearm. I also go into full paranoia mode in crowds. I'm glad you were able to bring that shield down. I don't know if I really want to, not completely. Still though, I hadn't really recognized that about myself until I read this post. Thanks for sharing.