Sedina was not what you would call a star student. Her aunt and mother were both on my speed dial for three years. She talked incessantly. She was stubborn. She was at her most joyful when she was being her most obnoxious self. Even today, I find notebooks scrawled in my furious, frustrated handwriting, documenting her transgressions and her blatant disregard of my authority.

Laura Klein

She was the first student whose name I learned. For anyone who doesn’t teach, let me tell you that the first names you learn are not the “good kids” or the teachers’ pets.

Sedina drove me crazy every day all year, and she pushed me to be better every day all year.

She was 80 pounds of confidence and attitude; very smart, and very social. She was the most natural leader whom I had ever met, at any age. She was the ruler of her class — a class that was notoriously difficult to control. I figured out early on that if I could manage Sedina, I could manage her whole class. (Like all students I write about, her name has been changed to protect her privacy.)

She could reduce a peer to tears in a matter of seconds, something that she did with a casual relish when she felt she had due cause. Kids still tell stories about her power.

One day a boy insulted her, and she spun on him, demanding that he take it back. He refused.

“Take it back right now, or I am going to make you cry in front of everyone.”

Again he refused, aware now that people were watching, and not wanting to back down publicly.

“O.K., I warned you,” she said, before proceeding to verbally dismantle him.

In seconds his head was in his backpack, hiding his tears, and she had turned cheerfully back to her math homework, having handled the problem.

Her sense of justice prevented her from feeling badly for this, and the next day she and that boy resumed their friendship as though nothing had happened.

I was her teacher for two years, and through our daily battles, we created a relationship that was somewhat interdependent. She wanted what I had to offer her — knowledge and support, attention and guidance. Despite myself, I admired her enormously — her feistiness, her ferocity and her vibrancy.

She was beautiful and strong-willed, and from the first day I taught her I found myself expecting more of her than of the other students — demanding more. As is always the case when you find yourself so invested in a student, I also found myself consistently disappointed, personally hurt when she didn’t live up to my high expectations.

During my two years as her primary classroom teacher, I watched her grow up — compassion and kindness slowly taking the place of the callousness that had characterized so many of her actions when I first met her. Then she went to a high school that allowed her to have an internship, and she came back to my class as an intern for a year.

All together, Sedina was in my life consistently for three years, and now, for the first time since I began teaching, she isn’t.

Perhaps all teachers have one student for whom they are teaching. Sedina was that student for me. Even now, when I am no longer her teacher, she’s still the one.

She is the one whose attention I sought to capture, whose understanding of a new concept showed me that I had taught it well.

She’s the student who would tell me that I was doing badly, who would demand that I teach it again if she didn’t get it.

She critiqued my looks, my clothing, my lessons and my life choices.

“Miss — why don’t you ever do anything with your hair? It’s just … limp, lying there like that.”

“Miss — don’t wear that again, you look terrible. No man is ever going to like you if you look like that. You look like an old lady.”

I loved her immediately.

Today Sedina is not the same girl I met four years ago. She is calm and self-possessed, confident but vulnerable. She knows who she wants to be, and works hard to be that person. She is aware both of herself, and of the world around her.

She still defends herself in inappropriate ways. She got into a fight early this year, resulting in a suspension at her new high school.

“I had to fight for my respect,” she explained to me when I showed disappointment at this turn of events. “I’m the new girl, so I have to show people that I’m someone to respect if they want to mess with me. I can’t back down.”

She reflects on life with wide eyes that neither distort nor accept the reality of the world in which she lives. When she learned about the 50 percent graduation rate in her high school, she quickly deduced, “because all of the girls don’t know about how they get pregnant, and so they end up with babies and drop out.”

This is not the future that she plans for herself. “I want to be one of those girls who is really smart, but no one would expect her to be smart because she’s so cute and cool,” she tells me, and she delights in surprising people with a good grade.

I have tried to guide her to use her power well.

“You are so lucky to be a leader, Sedina, but you have to be responsible with that power.”

“Why? It’s not my fault if people want to follow me. That’s their problem.”

“A real leader is someone who people will follow anywhere — you can lead people to do good things, or bad things. You could make people include someone, rather than leave them out.”

Sedina is a girl for whom I have high hopes — and she has those high hopes for herself. She has everything that she needs to achieve great things, and she has a hunger for the future that I rarely see in kids I teach.

I still have wonderful kids every year, and I have kids who push me and teach me, and who help me to grow as a person and as a teacher. There are many more out there who have touched me in a million different, important ways. But Sedina is the reason that I want to be my best.

I have had an impact on her. When she was inducted into the 10th grade National Honor Society this year, she sent me a message to thank me. We stay in touch, we go to lunch, we talk about the things going on in her life now, and her ideas about the future.

It’s a relationship that is very important to me — to see the way that she grows after leaving my class. After three years with her, my life feels a little bit smaller and emptier without her there.

Sometimes I feel bad for singling one student out as “special.” But perhaps all teachers need those students, to show you the best that teaching can be. I know that I need her, as an example of why I teach every day, no matter how hard or unrewarding it is.

She is a barometer of success — hers and my own. But perhaps more than anything, she is a reminder that kids grow up — that they transform, and that sometimes the worst-case scenario is not the one that comes true. Sometimes they become the best version of themselves, and that’s worth investing in.