PTSD isn't just for soldiers, and it has become more aware to many of our society as to the dangers and the importance of PTSD and how to treat it.
Now I saw treat but what we mean is avoid.
PTSD comes with triggers that may or may not put you back into the traumatic state you are trying to avoid.
My triggers tend to be yelling and such but if I am over stressed without even thinking about it I can go into my depression state of PTSD.
I have seen many kinds of PTSD triggers, even one as simple as repeating yourself can send some soldiers through the roof.
You never know what someone else is going through so sometimes it can be best to walk on eggshells until you know the boundaries.