Most of us are completely clueless in high school and the lessons will be completely forgotten. (Though I'm happy my province, Ontario, started doing this a few years ago.)
I agree that most of us get out of high school clueless, both because of age/maturity but also because schools are not teaching people HOW to think, they're teaching WHAT to think.
Two areas of knowledge would revolutionize the system, and obviously would never happen:
* critical reasoning -- this is I bought my kids a book on cognitive biases and how to think through problems and fallacies in thinking
* curiosity -- this is where AI would help in schools, but unfortunately teachers are pushing kids away from using AI in general, let alone using it as a tool to be curious and explore knowledge and reasoning about a subject
I can only conclude that these things are not inherently in the public school system on purpose to keep the population dumb and docile. I hate thinking that, but it's the only conclusion I can come to. Someone(s) wants our children to be dumb, dependent and easily manipulated in their thinking.
*
In the U.S., we had this for about 50 years, but was mostly gone by the mid-1980's. It was part of a class called Home Economics.
In some schools it was mandatory for everyone. In other schools, it was for girls only because at the time it started, it was usual for women to do the household finances.
The course often also included things like cooking, cleaning, and sewing. What people today learn from online "life hacks."
I'm glad I learned all of those skills in high school. I only rarely need to darn my socks, but the knots I learned translate to fishing and other needs.
It was also where I learned typing.
* proper nutritional eating
* balancing a budget (saving, spending)
* simple skills like how to stitch and sew their clothes when there is a hole or button needs to be fixed
I looked at their text books and my jaw hit the floor. All up to date, amazing pictures and instructions, little anime characters teaching life skills in a fun way. I was blown away, it was both practical and fun.
My daughter got a class like this in her charter school, they learned how to change a tire for a car and such. She absolutely loved it. They ran scenarios like, "if you made $<x> amount of money per year, and you want to live around $<y> how could you do it?", and she learned how she would get a roommate, how to split rent effectively and make a monthly budget.