Had to correct a guy once who walked in, put on his ears, set up, loaded a mag, and took a shooting stance. There were people down range to his left but he didn't look. I yelled. He didn't hear. I yelled REALLY LOUD and MEAN. He stopped, looked and thanked me. He wasn't a new shooter. Looked LEO or military to me. I think he was just preoccupied. No harm, no foul, and IMO a good lesson; or at least reminder.
Went to a friend's house recently. I had just helped this guy build his first AR. A friend came over, who had recently chosen a 10mm as his first firearm. His reasoning is that it is versatile (like a .357 but modern) for bad guys and animals. Also he can find ammo for 10mm while everything else is made from unobtainium. My buddy, not to be outdone, produces his new AR.
Both of them muzzle covered me and themselves. I call one of my daughters over and ask her the safety rules. She recites the rules, which have been drummed into my kids' brains from a young age, as they should be by any gun owning parent/guardian. The two dudes are like, yeah that's right, which is why we are careful etc. They didn't get the hint at all.
Both of those dumb a$$es, and a younger friend of ours, are going to a basic firearms class this evening. They paid for the class but I provided the ammo for the 9mm guys. New gun owners seem to be having trouble finding ammo. No idea why.
FWIW I have been shooting for ~50 years. Haven't been to a safety class in a long time so maybe I should go too. On account of complacency.
No one is immune.
Points being:
New gun owners are likely insecure about safety and therefore very careful at the range.... but potentially not safety aware or trained when at home and in their comfort zone.
New gun owners can often find guns to buy but not ammo. They are less likely to seek range training with ammo so scarce.
Complacency, nuff said.
One more thought. I was told in motorcycle safety training that the higher risk group was the mid-level experienced riders, not the younger riders. Not the older folks who been there, done that. I think gun safety shares that characteristic with riders.