Clearly you have neither spoken to a veteran at length, not are you one yourself. But here, I'll explain it. The reason you call multiple rules/laws "the first" is because they're all both equally and critically important.
Ask multiple veterans what the 1st rule of warfare is, you'll get multiple different answers. If you then reply with "I thought this other one was the first rule of warfare" they will reply to the effect of "yeah, it is."
Because firearms are dangerous tools that serve the singular purpose of killing or destroying a target, any target, and have been from inception to the modern day, every safety rule is just as important as all the others. Ergo, multiple first rules of firearmb safety.
It's called personal responsibility. You should learn to accept that some subjects are going to be taken seriously, because they are (literally) life and death circumstances. If you don't, they'll just be taken seriously anyways, and you're the asshole.
If I had to trust some internet rando with my life, I'd have no qualms choosing @Etterra@lemmy.world .
shrug I've already said what I need to, and nothing you said is unexpected or new. My opinion stands, yours stands, and time moves on. Have a good one.