'm sure I've told this before, or some of it anyway.
Let me preface by saying that, when I was younger, I was more than a bit reckless and there are very few things I did then that I would do now.
My first incident was with a person. My dog alerted in the middle of the night and ran silently to the front door. I grabbed my Ruger Super Single Six that wasn't officially loaded with .22 mag HP ammo and chased after. There was a guy pulling the front door shut to avoid my dog. I called my dog off, opened the door, aimed above the guy's head, and fired. He stood there... so I leveled it at his chest while cocking and began to slowly squeeze off. His paralysis broke and he ran, saving himself from a trigger-happy 16 year old. Dad found me in the morning barricaded behind the sofa, which I had pushed out, with all my .22s and shotguns. Not recommended.
I had several run-ins with feral dogs as a teen, and I consider them all valid self-defense situations. I chased one into the woods, found myself facing the pack, fired a couple at what I figured to be the alpha male, and ran. When I cleared the firezone I yelled to my friend to loose the 12 gauge with buck. We had pulled my Jeep's motor, were trying to rebuild it, kept getting stalked, and got tired of it, so the long guns came out in addition to our pistols. We later did some exterminating. None of this pack had collars.
The big one came when I was running security for a cab company while in college. I had gone on a high-risk run with the cabbie at night and when we got back to base, I saw that the plate glass window was busted in. I saw movement, so I told the cabbie to lock the doors and call the cops on the radio phone, then I got out and gave chase, pulling my pistol as I entered the shadows. I almost caught the guy too. But, that was just plain stupid. I was too gung ho, though in all fairness, I saw it as a personal failure and wanted to put it right in my employers' eyes, and my own. However, I should have stayed, secured the scene (meaning, kept everyone away from the place), and kept an eye on the cabbie.
The big one was the attack dogs charging me (documented several places already, no need to revisit on yet another post), years after I wanted glory, and just wanted to be left alone.
To those new to carrying, looking at my lessons learned, I would say this: Don't go looking for trouble. It finds you often enough as is. Keep a lower profile than you have in the past. You have a moral, if not legal (in your state), obligation to not escalate the situation. Example: In college I lived off campus. I took my clothes to a laudrymat where I encountered a bunch of young guys dressed in biker black with cheap knives strapped on everyplace. I was semi-surrounded and told that all the washers were taken (which they obviously weren't. I just said "Ok," and left. I was in the prime of my shooting skill at that point: a 20 year old body with no fat and all quick nerve and reaction. Though I wasn't as experienced in cover and concealment at the time, I could have likely made up for it with raw speed and talent. I'd already picked a spot on each gang member's body that I would hit, all likely lethal. But I didn't want to fight. I didn't even want to do laundry. I only did it because it needed to be done. I really wanted to go home and relax after classes and work.
Having a CCW permit is not a license to kill. It only lets the police know that you're a good guy, and as such, you're expected to act accordingly.
Just don't do anything that would fuel the anti-gunners or make a neutral party favor the criminal. I did this for too long and still regret it.
As for the physological effects of fight or flight, I experienced auditory exclusion and time dialation, but that was really it. I saw my sights and indexed them. There were a couple times I actually aimed. My hearing isn't the best but it's by no means bad yet. I have it checked monthly (Mom's a speech pathologist and has an audiometer). I don't show symptoms of firing a 9mm three times, rapidly, in an enclosed space. Some people are just like that: The bones in the ears separate and keep damage from occuring. Or maybe I was just lucky. I don't know. I don't remember being numb; I definitely felt the trigger, and I don't think I mashed it, though I'm not 100% sure I didn't. I don't remember feeling anything; I did think right beforehand, "S***, here we go!" (Mods, that was my exact thinking; I usually do not swear), and the pistol "jumped into my hand." That comes from countless draws and practice. I don't remember drawing; it was just there.
The least number of shots I've fired in 'defense' were two, with the max being six. The six were received by a 'possum that tried to climb my leg. Not knowing if it had rabies I shot it and kept at it until it stopped moving. The attack dogs got three.
I was a person who took way too many risks. I'm not like that anymore; I've mellowed. I hope you, the new CCW permit holders, read this and make sound judgements.
I am writing all of this in fear of being ridiculed. On another board when I posted something similar as a response to the same question as asked above, I was called a liar and fairly shunned from then on out. I hope this does not turn out to be the case here as I'm fond of this board. Maybe some just can't believe a person's capable of so many stupid moves. I dunno.
At any rate, read, read, read, and PRACTICE. Shoot skeet with your handgun. Your scores won't be high but you'll hit them now and again and you'll learn. For shear speed, pinshooting is good. I think the best practice is vermin elimination, but few of us are lucky enough to have a place to do that.