After reading what I had written about student appreciation for teachers, I promptly heard from several teachers. A university professor for instance, wrote: “Sometimes it feels like I’m living for the days when a student actually thinks to say thank you. Mostly what I hear is whining and complaining and I can only remind myself that I’m not in this business for the kudos.”

She is correct in her self-reminder, but she and the others need to fix something else in mind. A thank-you from students, as few as they are, will always please, but what really validates a teacher is the appreciation of mature alumni who have processed what was taught for years into a productive life.

(These teachers didn’t contact me in the brief time since my earlier commentary was published. I often send drafts out to people knowledgeable of the subject for their feedback, and these came.)

I wouldn’t for a moment devalue a student’s thank-you, but teachers need to be realistic about them. Some students are just nice and thank every teacher with no necessary reference to actual value of teaching. It’s the thing to do, and they do it. Good enough, for now. Accept what comes, but don’t exaggerate its significance.

When I began to teach high school in Michigan, I was a little envious of those popular teachers who always had students hanging around them and praising them. I thought I would like a little of that, and it would certainly encourage me. With a little encouragement, I would become a better teacher.

Then I noticed something curious. These were not the teachers visited by graduates. They came to seek out those who taught such esoteric subjects as math and Latin. These teachers were not those popular with current students. I talked with my assistant principal about this, and he confirmed it has always been this way. The teachers who are popular with students aren’t those most sought after later. Many of the teachers unappreciated by students are the very teachers sought after years later.

When I observe the dearth of thank-yous our daughter receives as a university professor, I appreciate the more what I experienced from my undergraduate students. The difference between the college in which I taught and hers isn’t very great. The decisive difference, I think, is between then and now. I noticed a deterioration in student attitudes when I later taught part-time in a community college, and it’s yet greater now. This is a generation of kids who feel entitled to respect they haven’t yet earned and who have the notion that everyone’s opinion is of equal worth, students knowing at least as well as their teachers.

So today’s teachers on every level need to exercise greater patience with immature and unsophisticated students and have more faith in their own professionalism than I did. It isn’t just that the students don’t think to say thank-you, but that they don’t know what this means — unless it is thanking them for being their students.

I would rather be appreciated by former students who have gained appreciation by using what I taught them than by current students who don’t know anything yet. And by former students, I don’t mean those who catch you at graduation. Seasoned alumni are more convincing. And the longer they have lived and themselves produced, the more rewarding is their appreciation. Even if it takes thirty-seven years, as it did with the former student I mentioned.

In the meantime, you live by faith in yourself. It’s more important that your teaching has worth than that it is valued at the moment by present students.

Even if former students never expressly thank you or celebrate your contribution to their lives, if you see one living a wholesome, productive life, you must know you had something to do with it. They are a credit to you, whether they know it. It’s crucial that you know it.