I still remember my 11th grade English class like it was yesterday. My teacher was someone whom my parents and I regarded, and to this day, continue to regard as a blundering idiot, who, throughout the duration of the school year, failed to teach me anything useful about English.
My teacher would grade my work unfairly. He liked to intentionally mispronounce my name in class and call me Slaytone. He knew I wanted to be a writer when I graduated, and found fault with my work, regardless of what other faculty members thought of its quality. I clearly remember my parents complaining to the school about the overwhelming and obvious arrogance and disdain. As usual, the school did little or nothing about the matter.
As the school year progressed, I began to get increasingly tired of my 11th grade English teacher, and especially his teachings, of which I deemed inferior and useless. Halfway through the school year, he assigned us reading assignments which included gay and lesbian erotica, which in addition to being completely inappropriate, made little sense to me since my teacher always spoke badly of gays and lesbians. He would typically single-out one student in each one of his classes to accuse of being homosexual, then make jokes as to their sexual orientation.
My English teacher carried around an old leather briefcase which resembled that of a famous writer; someone he was not, nor would he ever be. The man had little or no talent, but when faced with it, he would bring that talent down to his level. In some ways, he was a bully of a teacher, and yet, through it all, he made me a better writer in the sense that no matter what I wrote, nothing was ever good enough to pass his high, almost unreachable standards.
I kept a personal journal since my childhood, and throughout my high school years, I wrote about how much of an asshole my 11th grade English teacher was. Among other things, such as experiencing sexual abuse and molestation, detailed notes were kept about how the entire high school experience made me angry, and how my English teacher had continually embarrassed me in front of the entire class. I later destroyed the notebook following graduation as it seemed useless to keep painful memories around. Since then, I have archived all of my written notes.
The one and only thing I learned in 11th grade English was the concept and habits of revision. It seemed that everything I wrote that year I had to revise at least five or six times, sometimes spending several hours alone in my room agonizing over small and insignificant things like punctuation.
And for that, and only that, I owe a bit of gratitude.
By the way, I recently found this to be interesting, and somehow relateable to the topic: 33 Unusual Tips To Being A Better Writer
[Also, for the record, my senior year English teacher was a much better experience.]