In a sense, the English teacher telling you "this is what it means" is a bit like the science teacher saying "this is how physics works". It's a simplification of the real intellectual field to help people learn. Perhaps for some people the reduction is unhelpful though.

My experience is of being an analytical whiner throughout school, and then suddenly understanding the point when it was explained to me by a fellow analyst in university. I can't help wondering how much more I (and others) may have enjoyed English if someone had explained it sooner.