BIRMINGHAM—I saw you in the Publix parking lot. Your car’s gas tank lid was open. I wanted to tell you. But you were busy.

You were wearing nurse’s scrubs, a hospital badge, and you were changing your baby’s diaper in the backseat of your car.

Your other toddler was watching you have a meltdown. You looked like you were about to cry behind that surgical mask.

Right now, I wish there were a machine I could hook to my chest that would print onto paper the words inside my heart. I’m not always great with sentences, but I have a lot I want to say. Such as: “thank you.”

If you are a nurse, I can only imagine how tired you must be. I can’t begin to understand what nursing is like these days.

Alabama’s COVID-19 cases are on an upward rise. People are dying each day. And, well, I guess nobody knows this better than you.

You’ve probably been working yourself raw, pulling double shifts, seeing the horrors firsthand. And somehow, after you clock out, you still manage to do the grocery shopping, to pay the bills, and to change your baby’s diaper in the backseat.

Maybe you feel overlooked, a little invisible, and underappreciated. Maybe that’s why you’re so upset. Or maybe you’re overwhelmed with life right now, wondering if what you do truly matters.

You probably view your life the way everyone does. You see yourself going from Point A to Point B, doing your work. No big deal. You’re just one nurse among millions. If you don’t do your job, someone else will.

But you’re wrong. And it’s not just your job that’s important, your life is important in a way that you might never fully appreciate.

This is going to sound silly, but have you ever watched someone knock over a bunch of dominoes?

A few years ago, Liu Yang broke the world record for domino-toppling by setting up and knocking over 321,197 dominoes in Beijing. (I’ll bet he’s fun at parties.)

Yang worked for a month to set up his dominoes just right, painstakingly placing each one where he wanted it. He literally constructed an entire universe of dominoes.

Experts say that if Yang would have removed just one domino from his enormous design, the whole thing would have never worked. But it did work. Every domino fell in its choreographed sequence, and it was a record-breaking success.

That’s you. You’re a domino within a chain of 7.3 billion dominoes on this planet. You will never see most of us other dominoes. You won’t even know we exist. But without you, our lives wouldn’t be the same.

So I know you’re probably worried, mad, scared, depressed, overworked, underpaid, exhausted, and wearing thin. I know you are on the frontlines every day, treating fevers, administering meds, and—I can hardly bring myself to say it—removing urinary catheters.

I have a friend who is a nurse in a large hospital. She tells me that the hardest part of nursing is wondering if anyone sees you. Maybe you feel that way.

Does anyone see the trouble you go to? Does anyone ever tell you, “good job?” Will anyone ever understand the abuse nurses go through when patients get ticked off? Can any person ever realize how hard it is to raise kids while tying down a full-time job?

Probably not. But one day I believe you will look backward upon your own life and you will be shocked at how important your role was in this big mess.

It will be a subtle feeling that overtakes you. A feeling of achievement that will fall on you like an afternoon drizzle. You will have a deep joy in your stomach, one that’s powerful enough to knock your heart out of rhythm.

Maybe it will happen over supper. Or during a movie. Or at your son’s high-school graduation.

Maybe you’ll be watching him in his long gown and square hat and you’ll remember the night you once changed his diaper in the backseat. The same night you were tired from working an all-nighter.

Maybe it will all remind you of this troubled era we live in, back when COVID-19 was tearing at the fabric of society. Back when our world was stunted.

On that fine day your whole life will come back to you. You will remember all you did in the heat of battle. You’ll remember coming home from work late, the tears from exhaustion, the patients who died on your watch, and those who survived to bless you for it.

Your kids will be grown, and by then, the world won’t even remember how to pronounce the word coronavirus. We’ll have new troubles, and newer problems. But you will still remember.

Your hair might be gray then, and your joints might hurt from a lifetime of shuttling patients into hospital beds. But it will be the greatest sensation of your life because you will realize how much you contributed to this earth.

And you’ll realize that this beautiful, messed-up, weird, scary, but exciting experience we called life was made lovely because you were part of it.

I wish I could have told you this in person, but it would have been too weird, since I’m a stranger. Besides, you have much bigger things to worry about right now. Like babies. Groceries. And saving the entire world.

Also, don’t forget about your gas tank lid.