Except there are no "accidents" with guns. Negligence, carelessness and plain idiocy, you bet. Poor judgement? Not, alas, in short supply. But "accidents" involving the discharge of a firearm can always be traced back to ignoring these:
1. It's loaded. Always. If you unload it and set it down? It's loaded. If the nice man at the gun store checks it and hands it to you? It's loaded. Look, slugs of heavy stuff come out the business end moving very fast. You can't dodge them. You can't intimidate them. They won't magically change course once they are on their way. You have to be aware of them.
2. Do not point the muzzle at anything you're not willing to destroy. 'Cos, see, there are those fast-moving pieces of metal (etc.) that come out of that end. They make holes in things. You can't dodge them. You can't intimidate them. You have to be sure you're not going to get in their way, likewise other people, pets, and the widescreen you bought last week.
3. Keep your finger off the trigger. Until you are good and ready to make holes in things (in most cases, this includes having the target lined up in the sights, see Rule 4). You are not a superhero (and neither am I, though it's nice to be asked); if you are not ready to press the trigger, don't put your finger on it. People grab at things when they fall; they make fists when they are startled. This becomes even more pronounced under stress. You don't want to be grabbing at or making fists around the control that causes fast-moving bits of metal to make holes in things, do you?
4. Be sure of your target and what's behind it. Remember, the gun will make holes in things. If those things are you, your friends, the TV set, the wall and/or your next door neighbor's new truck, it will not be a happy time.
And here's the wonderful, happy news: the Four Rules apply no matter if you have a gun permit or not. You can be the baddest, meanest gangsta' of them all (or, for instance, a professional athlete playing at being one) and as long as you follow the Four Rules religiously (and avoid the popping of caps into those of your fellows wearing the wrong Colors or making improper Signs, restrictions about which I am very nearly almost sincerely sorry but that is how Civilization works), you'll be okay-fine. As will those around you.
If, on the other hand, you happen to be the sort of witling who does not follow and religiously apply the Four Rules, well. Ahem. There is indeed likely going to be, at some point, quite a loud sound followed by a trip to the Emergency Room. Or to the Morgue. Sadly, it is not certain it will be you making the trip, either. If you did happen to have a firearms permit, especially if you are not well-connected, it will probably go away, too -- and that will be the very least of your worries.
Everyone has moments of inattention, distraction, sheer idiocy. The purpose of the Four Rules is to limit the amount of harm you will do to yourself, to others and to property when they occur.