Here's one, not to hi-jack your thread.
I stopped by my bosses house last weekend to pick up a bandsaw to use with cutting kydex. Anyway he's a new gun user but not a new gun owner. He has a WWI colt 1911 (belonged to his uncle a WWI vet) that he's been wanting to sell because he doesn't like "that style" of pistol. He went and got it out of the safe and brought it out on the porch. He looked it over for a few moments "I've never looked at it in the sunlight" he racked the slide and handed it to me. Only it had a full mag in it and he'd just chambered one and handed it to me off safety and loaded... I made the mistake of looking at both sides of it before racking the slide myself to verify it was unloaded. I felt like an idiot for not checking when he first handed to to me, he almost got sick when this old round (looked 30 years old) ejected out on the porch. The one good thing was I held the slide back and released the magazine, at least I didn't rechamber a round.
A week earlier a friend of mine had accidently shot his wife in the chest with a 357 needless to say she didn't make it. Charges haven't been filed "yet" I'm sure he'll be charged with something...
It only takes one misstep and you'll have a lifetime of regret. Be safe.