I knew teaching, and teachers, and how to run a school. Just ask me.

After all, I had reached a milestone that must seem distant to my current students, who are studying to become principals. I had just earned my doctorate and had been a principal for more than 20 years. Some may have questioned my sanity because I was a middle school principal : and it takes a special kind of crazy to love working in a middle school, especially an urban middle school.

But I loved it. Every. Single. Part. Of. It.

The school was in the part of the city where drug deals happened everywhere, where a drive-by shooting occurred during school hours beside where our girls were having an outdoor physical education class.

The teacher was incredible and got the girls inside immediately. Lockdown was called. The students gave flawless descriptions of the car, the driver, the passenger doing the shooting, the kind of gun used, the license plate, the car shot at, its license plate, the driver of that car and were not hesitant to provide all that information to the police.

"It's no big deal," they told me later. "That happens in our neighborhood all the time."

The shooter was caught in an hour.

Our school was considered sacred ground by the two major gangs in the area. They permitted no one to paint graffiti on the walls or break the windows, and that sacredness held. We never saw the gangs; we just felt their presence and protection.

Say what you want, they respected what was happening in that school. We had no fence and did not need one.

This was the school where teachers went to spend a career. I mean a whole career. Some had been there more than 40 years. I have deep respect for that.

When I joined them, they told me there were problems with discipline, but they had come up with a plan the former principal had not wanted to implement. I asked them for their plan; it wasn't on paper, but they told me.

I said, "This is our school. We decide how it will be run, not the students. We are going to take back the school, using your plan." We did.

I won't bore you with the details, but it worked. Where they had had no assemblies the prior year for fear of violence, we had eight assemblies with no disruptions. Discipline referrals were way down. Students were learning. Teachers were teaching.

By then it was the time of year that is really tough for all principals, teacher evaluation time, and this one was no different. I was scheduling and completing pre-conferences, observations of all the teachers, post-conferences, then trying to make certain I stayed on schedule and didn't miss anything.

It was time to observe the teacher in the ED classroom. That was when I got schooled on what real teaching was.

If a student has a label of ED, that means they have an emotional disability. The term applies to "persons who are under the age of 18, who have had a diagnosable mental, behavioral or emotional disorder of sufficient duration to meet diagnostic criteria specified within DSM-V, that resulted in functional impairment which substantially interferes with or limits the child's role or functioning in family, school or community activities (definition from the Diagnostic and Statistical Manual)."

Depending on the seriousness of the students' behavior issues, they may be in the ED classroom for all or part of the day.

When I walked into the room, it was a mess. Fifteen-plus students. Fifteen-plus different kinds of chairs. I really could not even tell where all the students sat or where the desks were. Kids were everywhere doing who knows what. The teacher called them together, and slowly they gathered in a loose formation kind of facing the teacher. He outlined the writing assignment, which he had planned for the observation lesson, then told them it was time to get to work.

Since I had always worked in schools that had all general education classrooms, I expected the students to disburse immediately and start working. Well, nothing happened.

After a few minutes, one boy rolled his desk chair with three wheels over to a ramshackle desk and started working. A few minutes later, a couple of other students walked indifferently toward tables facing the wall and sat down. Others moved. Then a few more.

Inside, I was a mess. The teacher was silent. I was not getting the picture.

More moved. Within five minutes, all had rolled, strolled, wheeled or wandered to their own particular workspace, and work was commencing. The teacher of this unusual bunch had given no other directions. He had not attempted to hurry anyone. He was bent over one of the students answering a question they had, not even looking at the slow exodus that resembled Moses' wandering in the wilderness for 40 years.

It was then that I noticed : all of the students were at work. Some calmly, some feverishly. Occasionally one would ask another a question but then would get right back to it. The work, that is.

I knew these kids. "Frequent flyers" I called them in my mind because they were often in the office. But here, they were under the direction of a master teacher who knew how they ticked, what motivated them, how to reach them, the things that caused them to think "I've got this!"

Here, they were accomplishing a mission, completing a planned writing assignment, some humming, some singing under their breath, one making noises that defied definition. But all were working. On something I had personally hated in middle school : writing!

Now it was my turn. I started feverishly taking notes on the teacher's evaluation, one that I realize now I should have saved because, well, because if I had it to write now, 16 years later, I realize how I should have written it up.

One word. Genius.

This was a teacher in a class of students who many teachers would honestly have preferred not to teach. A teacher who loved his job so much that it was all he talked about.

Did he meet all of the boxes that are supposed to be checked off when I evaluated him with a form that had been carefully crafted by a team of administrators? Perhaps not even close.

I don't even know where in today's system of teacher evaluation of four distinct levels (Highly Effective, Effective, We Don't Know What to Call You and Get Out of Here), he would score according to the system of check marks and evaluation comments.

But in that classroom, tucked into the back of the building in what had been a storage room that he asked to convert to his room, teaching was happening of an order higher than I had ever seen in my 19+ years of administration up to that point.

Not all great teaching checks the boxes on an evaluation, but this guy's teaching did. That day, he taught me. No, let me be perfectly honest. That teacher schooled me. And I have never forgotten it.

Today we are facing a teacher shortage unlike anything we have ever seen, of epic proportions. It is not that we do not have qualified teachers or are not producing teachers or even that too many have retired. In my heart of hearts, I believe it is because we have forgotten to say thank you to all who teach or have taught.

Most of the time, I write about the politics that influence public education. But this time, I just wanted to take a deep breath and say thank you.

Thank you to all who teach. Thank you to those great teachers who go to work every day not knowing what that day holds. Teachers who may never win an award for spending that extra hour preparing a special lesson that will reach every child in your room. Teachers who face criticism they do not deserve. Teachers who lose sleep trying to think of one more way to make a difference in the life of a student who has failed in every other school she has attended, but is trying in her new school. Teachers who have been told they are the best a principal has ever worked with but they are afraid to believe it because it's easy to get discouraged when there is still one more paper to grade and one more assessment to plan.

Hey, teacher, this one's for you. Thank you. I hope it matters that I think you are amazing. 

Fort Wayne resident Michael Shaffer is an assistant clinical professor of educational leadership at Ball State University.