My highschool teachers didn't (European school, too). I found it by myself one or two years later (I hated trig in the meantime) and was very proud of my achiev

My highschool teachers didn't (European school, too). I found it by myself one or two years later (I hated trig in the meantime) and was very proud of my achievement. Then I went to university where all the teachers were treating it like a natural thing, and that was my first glimpse of adulthood -- I started realizing I was really stupid.