My school tried really hard I think. They showed us budgets, and explained compound interest. We had seminar days in ~7th grade where they showed us how to balance a checkbook and in high school how to take interviews- and we did mock sessions. Sadly, I didn't have a lot of buy-in. They didn't talk much about credit cards though, which seems a big omission. I also don't remember seeing any "woe be you" examples of how something like a 25% interest rate on a credit card can sink you. I think a little fear, or promise, or both, added to the mix, would have helped a lot.
My parents did really well actually explaining investing and stocks, although of course with the Old School view- you pick individual stock, you get an advisor and do mutual funds, tax optimization is the most important thing, taxes are too high, etc. They did a really good job with cars- buy in cash, keep the car until it doesn't make sense to fix it anymore, and so on. I wish I had learned some DIY skills with cars, but I did learn them with other areas, so I can't complain too much.
All in all, I think school and parents did pretty well. Especially given that I was in a public school and my high school has pretty bad graduation rates (well, about state average haha, Oregon only has a 75% high school graduation rate- we're one of the worst in the nation, go us!).
2 things should cover almost anything.
1. Time value of money. That Latte is not just $3.00. It is also all the lost revenue that $3.00 would have generated forever. Want the $3.00 Latte everyday? Fine. Have NONE of them until you save $27,375. Now you can have 1 every day for the rest of your life.
2. There is still very little discussion in the US of how much is enough. My father, who is 77, is still working full time as an owner in a business he has hated for the last 25 years. He can not spend what he has earned, and is just now beginning to realize "Why am I doing this?". I tell him I have no idea. You are not doing it for me, because I retired 2 years ago.
This would have been a big one. The idea that, at a certain point, you're allowed to be content. You can stop striving so damn hard when you meet your goals. The goal isn't always "more" to have a happy life. I wish my parents realized this, and I wish they instilled it in me.