Hypervigilance - it's been around forever, of that I have no doubt. But it's not a word I ever heard mentioned in all my many years of formal education. For a more thorough definition, have a look here, but whether or not it's something you personally have experience with, doesn't negate the fact there are a lot of people out there standing on guard, waiting for the next blow to fall. I'm one of those persons. It's a bit unfun. For me personally, it's not related to PTSD - I haven't been subjected to military combat or sexual assault, and for that I'm very grateful. But for one reason or another my nature and nurture cooked up a little concoction that makes me hypervigilant - all the time. What does that mean? It means I'm always on guard.