Finance by itself is not that complicated. If you know the underlying maths, that's the kind of thing you can learn on the spot, at least on a basic level. If you want more than that, you probably should hire an accountant, or it becomes specialized studies.
For the rest, I don't know what kids learn in the US but I guess things like the great depression are part of the history lessons. Do they teach that without any insight about the economics of it?
So there you have it, you know the stock market and taxes exist from history lessons and you learn the mathematical operations to run the numbers. I don't remember learning about the legal aspect of finance (which may be the most important of all), but we certainly had on overview on how the legal system works.