If you are in your mid to late 30's (in the USA maybe other places too) then you may be able to relate to this... Everyone invited to add a comment.
Perhaps it was my schooling, and mabye the elective subjects that I didn't choose, but here in the USA is a small list of subjects that the schooling (k through 12) should have elaborated on. Maybe the school system assumed we knew all about these topics (which were semi-current then).
[*]Basic Stock Market (Knowing this could have changed my life long ago).[*]Elaborated more on Korean and Vietnam wars (I must have fell asleep in class, can't remember anything from school on this).[*]Martin Luther King and others like him (I think a teacher mentioned his name once).[*]Real sex education (we had this, but not like today's standards. AIDs wan't around then either).[*]Psychology (this may not qualify as anything here, but I believe there should be a manditory subject on this at sometime in high school).
Feel free to add to the list. I am sure there is more that I could add, but since I wasn't aware of it, then I missed it.