This is trauma: You are walking along the path you always take, when suddenly the ground cracks under your feet like rotten ice, and you fall. You're shocked and terrified and you think you're going to die. Then you slam into the bottom. Maybe you break some bones, maybe you're just shook up and bruised.
This is normal recovery: You climb out of the pit. You go to a hospital. Depending on the extent of your injuries, recovery may be long or short, but after some length of time, the casts come off and you get on with your life. Maybe you're a little more cautious about where you put your feet, but it doesn't interfere with your life.
This is PTSD: You break bones at the bottom of the pit. You move to get out, and the bottom of the pit crumbles just like the path did, and you're falling again, stuck in that same moment of terror and shock and pain. And you keep on falling, and you will fall forever unless you grab a rope.
Grab that rope.
Dangerous Jam - A User's Guide to PTSD, Part I: What I Did In The War
This is amazingly well written and rand a full hand-bell choir of bells with me. I may not have been in a war but I have experienced first- and second-hand trauma at many times in my life, especially my childhood. This is also probably why certain words (e.g. 'spaz' or 'spazzy', 'flid', 'mong', 'gay', and so many other disability- and social-status-related words), trigger the F* out of me and cause an aggressive verbal fight response (which I can neither lessen or prevent and which causes me to feel ill in a very real and immediate sense). I would love to be able to temper/lessen that response but all I can do is hope that I can step away from the causal situation, that perseverating upon the cause will not magnify the trigger and that I can avoid the trigger in the future.
I am now off to read the other parts of this essay-series and maybe plurk/tweet/share a link to this post.
Edited to add:
intense psychological distress at exposure to internal or external cues that symbolize or resemble an aspect of the traumatic event.This is from part II.
Also from part II:
These reactions are impossible to control because they're faster than thought. You don't realize what you're doing until you've already done it. And then, typically, not only are your nerves even more jangled by the adrenaline that the stimulus dumped into your bloodstream, you probably feel very embarrassed by your reaction, and will frantically try to figure out how the hell you can explain it. Especially if you reacted violently.
From part IV:
PTSD is not actually helpful protective armor but rather a set of massively counterproductive and painful reflexes that can feel like they’re all that stands between you and your own destruction.
 I was told this by my therapist. I am not making any of this up. Note that I am in the UK and that our definition of PTSD (and my diagnosis) may differ from that in the US or elsewhere. We do not use the DSM over here.