If you're lucky, you have a truly good teacher in school.
I had a couple. And one of them was most definitely my high school history and civics teacher, Mr Leonard Helton, whom I just learned died a month ago.
In those days, Mr Helton was a vibrant, dark-haired, bearded man with glasses. He came from Morgan County, Kentucky, as he never ceased to remind us, and brought his unreconstructed Kentucky hills accent to teach the advanced two year course in U.S. history and civics, an option for the brighter students who wished to opt out of the shorter standard courses.
This wasn't a standard course with a strict lesson plan. There was, for instance, no textbook; our reading was self-directed at Mr Helton's personalized recommendations. The course was more of an opportunity for Mr Helton to give free-form lectures, full of humor and anecdote, but always at the service of the pedagogical point, and to engage in conversation and debate with students. He always came out best in the debates, and not just because he was more experienced and knew more. He was just a better debater, as proved by the time he invited the vice-principal to come to the class and debate him on the topic: Hamilton or Jefferson, which political philosophy is superior, and more at the root of American political culture? Mr Helton allowed his opponent to pick either side (he picked Jefferson, so Mr Helton took Hamilton), and not only did Mr Helton come out best in the debate, he said he'd have done so the other way around, too.
What I learned most concretely from him was not topical, but on how to write a large research paper, a form of work he passionately advocated. I wrote two large papers for him, one on the geography of the Lewis and Clark Expedition and one on the formation of California's first state government, each large enough, at least in wordage and amount of work put in, to have served as a university senior thesis. (As I know because I wrote one of those, too.) It made the work when I actually got to university seem easy.
At the end of the course in my senior year, Mr Helton picked three of his prize pupils (two boys and one girl) and had us take the College Board Advanced Placement test in American History. We gathered in the school office one quiet Saturday, pop-quizzing each other on the way in ("What was the Truman Doctrine?"), and Mr Helton proctored us. We all got the highest score, and to our scattered univs went with the seal of approval of the toughest, brightest, sharpest, and most challenging and enlightening history teacher we could have had.