I dropped the handwritten thank-you card into my “good mail” folder in the file cabinet under my desk. That’s where I keep a few of the best notes mailed from readers.

I had no idea Ria Van Ryn had been dying of cancer when she sent it. Maybe she didn’t even know herself.

I first heard of Ria when she taught my daughter’s English class in ninth grade. My daughter mentioned that “Dr. Van Ryn” was a tough but excellent teacher.

Someone with a doctorate, teaching freshman English in a public school? That’s a little unusual.

It turns out that Ria often chose the unusual path. She had just left a tenure-track teaching position at Yeshiva University in New York City -- a position she earned after getting one master’s degree in religious studies, as well as another master’s and a doctorate in sociology.

But it was too expensive to live in Manhattan on a young academic’s salary, and she had a dream of becoming a mother.

So she headed back to St. Louis, where she had been raised, and where her mother and one of her sisters taught in her childhood school district. She earned her third master’s degree -- this one in education -- and a teaching certificate before getting a job teaching high school English and social studies.

Raised Unitarian, Ria had converted to Judaism in graduate school.

Her dissertation focused on a Jewish day school and a Muslim day school: She was interested in how children followed their parents’ religious traditions and how they learned about other religions. At the end of her project, she brought the kids together for a day of service and a shared meal.

As devoted as she was to her students, she wanted a child of her own. She was single, and decided to pursue fertility treatments. It took a year to get pregnant.

She gave birth to Schuyler in August of 2017, when she was 37.

Her family was thrilled.

“She was Jewish by choice and a single mother by choice,” her sister Trina Van Ryn said.

Ria told her parents, Debbie and Jack, that they were going to be co-parents with her. A tight-knit family, they call themselves Team Van Ryn.

In July of 2018, when Ria’s eyelid started drooping, her father urged her to have it checked out. A CT scan showed she had gastrointestinal neuroendocrine cancer with tumors in her chest and stomach: a rare, aggressive and unpredictable cancer.

Her daughter was 11 months old.

Ria didn’t want to know the survivability rate; whatever it was, she had every intention of beating it. She had been a state-level swimmer in high school, and had run 13 marathons. She would fight this.

Her father, an orthopedic surgeon, knew the odds.

The family kept their fears and grief to themselves. They were Team Ria.

“We will be with you every step of the way,” her sister Zannah told her.

Ria filled a binder with information and questions, and carried it with her to every doctor’s appointment. She went through seven different chemo and immunotherapies in 15 months.

She also kept teaching.

During this time, she emailed me -- “at no small risk” to herself, she wrote -- to talk about incidents of racism in the school that concerned her. Eventually, she took her concerns higher, personally meeting with the district superintendent.

“What do I have to lose?” she told her mom. “I have cancer.”

Her family rarely saw her cry -- only when she talked about wanting more time with Schuyler.

But she never talked about dying.

Shortly after Christmas, my daughter’s principal emailed the students and parents about Ria’s death. When I read her obituary, I realized we had both graduated from Trinity University and majored in sociology. She had taught my daughter, and yet we had spoken just once, about a story tip.

Ria’s Unitarian family sat shiva for her.

On New Year’s Day, three days after her death, Schuyler asked her Grammie and Opa, “Where’s Mama?” She knew her mother had been in the hospital and sick, but she wanted her now.

Both of them took her by the hand and walked outside.

“See the sky, where it’s so blue?” Jack said, pointing up. “That’s called heaven. That’s where Mama is, and there are no boo-boos in heaven. Mama’s going to stay in heaven, but she wants you to stay here with Grammie and Opa.”

Two-year-old Schuyler looked up to the sky and said, “Hi, Mama.”

She turned to her Opa and said, “Mama blew me a kiss.”

I wish I had written back to Ria when she sent me that note a few months before she died. I think about the writer and reader my daughter has become. Ria helped do that.

Through the lives she touched, she’s blowing kisses back to all of us.

Earlier this week, my 14-year-old son asked a startling question: Do you think there’s really going to be World War III?

Like most kids with a smartphone and access to social media, he had seen the chatter about war spiking after President Donald Trump ordered an airstrike that killed Iranian Gen. Qassem Soleimani in Iraq. From mushroom-cloud memes on Twitter to TikToks about dodging a possible draft, teens processed their anxiety, ironically, on anxiety-provoking social platforms.

World War III hashtags started trending again when Iran retaliated by firing missiles at Iraqi air bases housing U.S. forces.

Gen Z found a way to mock the fears that gripped most informed adults about the potential for escalation in the conflict with Iran. It makes sense, given the outsize role violence has played in their childhood. War is both near and far in their imagination: They’ve grown up in an era of never-ending war, in which America is time and again dropping bombs on some far-off country. Meanwhile, their schools are regular settings for the mass murders of their peers, to which our leaders respond by having children role-play being stalked and killed by a mass shooter. Children can watch animated videos on YouTube about what would happen in a nuclear war.

How do we expect them to cope? They see adults unwilling to protect them from the existential threats facing their generation -- from gun violence to environmental catastrophe -- and willing to excuse and protect certain evil regimes in which they have a vested economic interest.

The kids aren’t stupid.

The notion of a third world war, in particular, is tied to fears of a nuclear war and annihilation. Those of us who grew up during the Cold War understood those theoretical risks, but we didn’t face those apocalyptic ideas bombarding us when we simply wanted to talk to our friends. Or watch a video. Or play a game.

When the prospect of war looms, my thoughts go to the people I know who would be most directly affected. As soon as I saw the news of the strikes on Iraqi air bases, I texted our close friends whose son is an officer in the Air Force and just returned last month from Iraq. He had been stationed at one of the bases attacked.

“Just pray he doesn’t have to go back,” my friend said.

I opened Facebook and saw another friend had posted a prayer request for her niece, stationed at one of the targeted bases, taking shelter in a bunker.

I think about the funerals I covered of young American soldiers from the U.S. invasion of Iraq in 2003. While no one knows exactly how many innocent people have been killed and wounded in Iraq since that invasion, the Watson Institute for International and Public Affairs at Brown University reports that more than 182,000 Iraqi civilians died from direct war-related violence. Civilians. Brown’s Costs of War report found that the U.S. “War on Terror” has cost the U.S. $6.4 trillion and led to the deaths of 335,000 civilians worldwide. That’s more than the total number of deaths in Hiroshima and Nagaski combined. In the case of Iraq, the argument about “weapons of mass destruction” given to the American people to justify the war turned out to be false.

Maybe that’s why the dark humor war memes seemed chilling to me. We know that the things we want to believe could never happen are entirely possible.

To answer my son’s question, my impulse was to be as reassuring as possible.

“No, I don’t believe World War III is going to happen,” I told him.

To myself, I said a prayer.

A decade ago, I started a simple list.

We were driving back from visiting my family in Texas during the holidays, which is always among the best things I do each year, and I was feeling sentimental. I started jotting down bits and pieces from the past year. I called it the “Best of 2010” and came up with a top 10 list of just a few words -- a destination we traveled to, a visit from people I love -- my highlight reel of the moments when I had felt most joyous.

Looking at that list and reliving those moments felt so great that it prompted me to make another one. I wrote the names of the people who had been especially vital that year -- the people who showed up for me when I needed them the most. I titled that list simply “Team.”

I resolved to find a way to thank those people, sooner rather than later.

The whole exercise probably took less than half an hour, a way to kill time on a long road trip. But it felt like a satisfying way to end one chapter and start the next: focused on the good and feeling grateful.

I decided I would try to make my “Best of” and “Team” lists an annual ritual. I had started it as an email draft to myself, and I eventually compiled it in a Google doc. When something particularly wonderful would happen during the year, I’d open the doc and make a note of it. At the end of the next year, I was culling a work-in-progress down to the most essential moments, rather than starting from scratch.

So now, I have a full decade of those moments and names to reflect upon. I’ll confess that it’s a little more than 100 in total, because some years I couldn’t bring myself to limit it to 10.

I’ve created a longitudinal dataset of my own happiness.

Indulge my nerdiness while I analyze it.

Some expected themes emerged: vacations and holidays with families, celebrations like weddings, visits from friends, special sporting events and concerts, new experiences and milestones for our kids. Obviously, Big Moments aren’t always good times and laughs. But the patina of nostalgia smooths over the stress and conflict that we may have experienced at the time. I often rely on a measure of distance to help bake in the fuzzy, warm feelings and minimize whatever chaos and discord bubbled in the background.

Selective amnesia goes a long way toward familial harmony, I’ve learned.

I discovered some surprises in my dataset, too. The times my work connected with readers, helped someone in a difficult situation or was recognized by others consistently brought me joy over the years. It’s a good reminder that finding meaning and purpose in your work is key to personal happiness.

Another repeat item involved taking on difficult challenges -- like running a marathon, making a film, applying for fellowships or managing a house renovation -- and just being able to complete it. I didn’t win any races or film awards, but working on something hard and being able to finish it ended up on my top 10 list nearly every year. The funny thing is, when I’m in the depths of a project like those, I’m usually miserable -- stressed and full of despair and regret for taking it on.

This turned out to be a great way to check in with myself and my relationships. It’s given me a roadmap on how to prioritize in the future. And the older I get, the nicer it is to have a handy timeline of life’s bright spots.

It’s also been a way to reset my perspective at the start of each year. I read depressing and enraging news stories every single day, and I’ve found a way to make an antidote for myself.

May the next decade be just as list-worthy.