My woodworking teacher in highschool was missing two fingers on his right hand. I don't think anyone is 100% safe around tools, child or adult, educated or otherwise. Life's about risks and how you manage them.

Which is not to say that kids can't be trusted to use tools! It's just that they're probably more vulnerable to overconfidence and complacency than adults, who are by no means safe from these things themselves, so it's probably better to let them cut themselves once or twice on a sharp knife before you let them use something with more permanent consequences, like a bandsaw.

In my observations the most overconfident and complacent tool users are the ones with the most experience, not the least. But perhaps it depends on the kid.

I probably stated that the wrong way. I think kids are more prone to overconfidence at any given skill level than adults, and checking in on them helps reduce the risk. It also helps for adults, but we're mostly not responsible for what adults do.

Your mind will play tricks on you, the last thing you'll think before the accident is 'this is safe'. In machining a technique to fight that thought is - don't touch anything with your finger that you wouldn't touch with your 'pecker'. With falling asleep while driving you'll often think a little nap wont hurt - an absolutely ridiculous thought in hindsight but you're not working with 100% of your faculties 100% of the time.

There are many activities where accidents are rare but severe resulting in overconfidence. In activities like motorbike riding or gliding aircraft people will convince themselves that they're skilled enough when all that has happened is that they've been lucky, and given enough instances their luck will eventually run out. Knowing the stats can help avoid confusing luck with skill.

I generally study the stats and even I get caught out, usually when working while fatigued so I simply have to refuse to work when that happens - the accidents are not worth it.