Assume you’re an idiot
Tam distills all the rules of gun behavior down to one: Assume you’re an idiot.
This works for me, because it’s something I already do.
Today I climbed on top of a machine about thirty feet tall. If I had been thirty feet up a rock cliff, (Which I have done, in my skinnier days) I would have been scared shitless; the fact was I wore safety equipment against falling and though I was in some precarious positions i was never in any real danger.
The inherent danger of firearms makes it important that you follow safe handling rules, and frankly, I strive to be ever more anal retentive about safery- but I have to say, I like Tam’s rule.
I tend to apply it to almost everything I do, because I do a lot of other things that are inherently dangerous. Bluing guns is basically playing with five gallons of boiling lye. All woodworking tools are potentially lethal- if you got your hand in a Lauderdale chop saw, for instance, you would bleed out before it let go of you. Metalworking machinery- don’t get me started. Welding, cutting steel, forging… Just about everything I do offers me an assortment of amusing and varied ways of snuffing it, or at least causing myself serious bodily harm.
So I assume the next move I make is the one that’s gonna get me killed. As often as not, even being careful, I need to be able to get the hell out of the way quickly. And all this is amplified by the fact that I have SEEN the injuries of which I speak; there are a number of friends who I’ve buried or visited in hospital after having been harmed by industrial machinery. And if you want to see gruesome injury, go to a farm.
Good advice, that. Assume you’re an idiot. You won’t be often wrong.

Yesterday a student managed to run a vehicle off one side of an ramp style alignment rack. The next twenty minutes involved jacks, bunker blocks, and me planning every step as carefully as I could. They understood everything but the planning…. and I explained to them “I WILL NOT call your folks to tell them you were crushed by a car today”.
I guess it’s just something you learn over time, if you are lucky, and pay attention.
I’ll never forget the guy in the press department at Stewart-Warner years ago, who saw that his workpiece was out of position and managed to get his hand into the press to try and correct it AFTER the sweeps had fired but BEFORE the press came down.
Me, I think I would have accepted the ruined piece before accepting ruining my hand…the latter being what happened to said pressman.
My great uncle, a shop teacher, lost his fingers to either a jig- or circular saw. When he saw students who were being unsafe around such equipment, he would just lay his hand down on whatever they were doing and not say a word. Worked every time.