Never Forget. It became the mantra that followed Sept. 11, 2001. For me and my wife, it started with the ever-dreaded sound of the phone ringing too early in the morning. Moments later, we stood before the television — as did all of America — overcome by grief and confusion as the horror of the day transpired before our eyes.

Seventeen years ago, I would have sworn this country would always remember our national and worldwide suffering on that date. Last year was the first year I left my home in the morning and returned at night without hearing one person mention 9/11. It was the first time since 2001 that I saw some flags flying at full staff. I fear we are getting complacent.

I teach children. Every year I teach them about this part of our history. I’m careful. Many details and questions I leave for parents to address. Each year I’m reminded how unfathomable the discussion is, how it can’t be truly explained or justified in any meaningful way to young and innocent minds. Yesterday we covered pronouns and solving word problems with addition, and today we sit down at the rug and talk about why Sept. 11 is a day we treat with respect, why the flags are flown at half-staff. They learn the word “solemn.”

For most of my students, it is the first time they’ve seen a teacher cry. Even my most impulsive students resist the urge to interrupt; they listen in complete silence.

It’s a lot to present, and I bear in mind their age. I focus on the bravery, dignity and selflessness rescuers demonstrated throughout the day, and in the days that followed the attacks. If I’ve held it together until I get to the firemen, the police, the first responders, and the rescue dogs, all the heroes who risked or lost their lives to help strangers, well ... it’s happened more than once that a 7-year-old took it upon themselves to bring me the box of Kleenex that lives next to the sink.

One nation. Indivisible. United. Honor. National strength. Bravery. Heroics. Collectively these words may almost sound cliche to adult readers. However, to children they are ideals that must be learned; ideals that they are not presently seeing or hearing being attributed to many of our leaders when they see the news. (Sen. John McCain was a rare exception).

Sept. 11, 2001, was the last time we stood indivisible, our example set by the members of Congress as they joined on the steps of the Capitol building and sang “God Bless America.”

America does not need to be made great again. It has never been perfect, and it never will be. But it has always been great, and when we do stand tall, we do so like no country in history. We have always done so when pressed upon, and I believe we always will.

As rancor and schisms tear at our national unity and, as a direct result, our national strength, it is crucial that we teach our children the powerful meaning of the words: The United States of America.

I hope this Sept. 11 you found time to put your busy day on pause, put down your cellphone, sat with your children and reminded them about the importance of this date in our history as a nation.

This year and the next — and the next after that — we have to show them how to honor those we have lost, and those who continue to serve and sacrifice for America. Teach them the meaning of the phrase: Never forget.

Christopher Rodarte teaches at Sam Hughes Elementary School.