Back in the days when I had no idea of what was actually required to be a good teacher, back when I was in grad school studying education theory and making foolish assumptions about how to manage students, I walked in on a conversation in a teacher's lounge that would change my life.

I had recently fled—yes I said fled—an elementary school on the West Side of Chicago. My year of student teaching had begun with the principal telling her staff that she hired us because we were physically attractive and that she loved the "green stuff" (gesturing money with her fingertips) and thus would have no problem firing any of us to save her job. She frequently used the P.A. system to spread her tyranny. Once she announced basketball try-outs and bluntly added that students who weren't skilled at the game should not show up. "I like to win," she said.

I shared a class with a mentor teacher who passed out worksheets all day and once responded to an insult from a student by saying, "You're talking about yo' mama." Some days I felt more like a bouncer than a resident teacher because I had to break up fights in the hallways and shout at the top of my lungs to get students' attention in class. I knew that if I were to gain any positive teaching tools, I'd have to go to another school. So after six months, I fled. The split was so messy that I didn't get a chance to say good-bye to my students. I ended up finishing my training at a progressive public school on a different side of the city.

That's when I stumbled in on that life-changing conversation in the teacher's lounge. The chatter was animated. A few teachers were reminiscing about their classroom horror stories at other schools: John dashed out of the classroom ... Sarah threatened to jump out the window, again ... Angel knocked over bookshelves in a fit of rage .... And in my desire to fit in and one-up the last tale, I began to share about the unbelievable dysfunction at my old school. Even though I hadn't yet earned my teaching certificate, I felt like I had earned some stripes. I was persevering to educate the youth despite the insanity within the urban public school system. I was the heroine of the story, fearless and unafraid.

"It happened to them," were the four words that shut me and the other teachers up. "It happened to them, not to you. You tell the stories like it's some kind of entertainment, but it happened to them—the kids. They are the ones who 30 years from now will remember these stories with tears in their eyes."

It was the middle school social studies teacher. He was a demur white man in his late 30s who often wore cardigans like Mr. Rogers. Until then he had kept silent, even as each story gave rise to a higher level of ridiculousness. He went on to explain that he, too, used to complain and feel like the victim until another teacher rebuked him with those words. He felt compelled to pass that wisdom on.

It happened to them: This truth has haunted me for the past eight years I've been teaching. I am only glad that I got set straight early in my teaching career. Some teachers never seem to get it. You know this when their debates about education reform are centered around teacher rights, and not student rights. Teachers' needs are important—I have a mortgage; I have a family; I would like to retire one day—but they are not the core issue. The mission is bigger than us. Educators and policymakers must boil the chatter down to two essential questions: To what degree will this policy enhance student learning and how will we know?

My children attend the school where I teach so I am all the more aware that "it"—whatever "it" is in a school, good or bad—is happening to them. I have to continually raise my expectations for myself, as a practitioner and as a parent. I must think deeply about what I believe, and then advocate for it. I can no longer rely on the teachers' union (if I were still in one) to represent my views and values about education. I must be like that social studies teacher who took a risk and spoke up for what was right. That is the only way anyone has ever changed the world. And that's why I am "Charting My Own Course."