I don’t believe anyone managed to learn anything useful about history or economics or literature in high school. Or about anything else. I wish more people were able to seriously study these subjects as adults with the guidance and correspondence of a global community of fellow students and access to centuries of past discussion and debate.
People telling you there’s nothing more to learn (or that the “soft sciences” offer nothing better than your personal intuition) are the scammers.
It’s worse than that, most things you learn in high school end up being either false or so simplified it ends up misleading (think common misconceptions). Biggest offenders tend to be history and hard sciences, although that might be mostly since we don’t even offer things like psychology or sociology outside of a few elective APs (and imagine how prone to misinformation those classes could be if taught by someone following their personal intuition!)
Dunno how it is in other countries with a recent slave past, but Brazil did an excellent job in erasing both native and African ethnicities in my school years. You never learned about specific native tribes like the Aymore, Tupinamba or Goitacaz, it was always “the natives” and all African slaves were just that, “African slaves”, no difference between the ones from current day Mali, Angola or Somalia.
Whenever the books talked about the expeditions into the heartlands, the bandeiras, they rarely or never mentioned local tribes that might’ve helped them, whether in goodwill, in exchange of something like getting rid of old enemies, or by force.
Another thing that school glossed over was one of the many slave revolts, the Malês Revolt. I vaguely recall that the book said that slaves organized by leaving written notes, but it never mentioned that said notes were written in arabic, because those slaves were from Mali and most of them were muslim, thus they could read and write in arabic. It also never taught us that, after the revolt was quashed, nearly every slave from Mali was sent back to Africa and the city of Salvador, the focus point of the revolt, expelled every muslim and removed every mosque it had.
Man, I could go on for a while, just comparing what I remember being taught in school and all the stuff left out that’d make me really damn interested in paying attention to classes.