At a work dinner recently, I was seated next to two people whose children are adults. I can’t recall now exactly how old, but theirs were certainly more grown-up than my second-and fourth-graders.

I’m often drawn to parents at this stage of life; their very existence — coherent, unhurried, able to order at restaurants without asking if the chef could ignore his Michelin rating and kindly just make buttered pasta, thank you very much — gives me hope for my own chicken-finger-free future.

And so I found myself listening intently as they discussed their children’s comings and goings from college; a child engaged; another wanting to start a business. I was fascinated by their tales of such accomplished, self-propelled, interesting creatures who have jobs, send photos from their travels abroad and don’t “forget” to flush the toilet.

But I was most intrigued when one of my table mates started talking about all the things she stressed about when her children were young. “The funny thing is,” she said, “not one of the things I was so worried about turned out to matter at all!”

She said it sagely, like a woman made wise by the absence of “Nick Jr.” show theme songs playing in her head. The other veteran parents mmm-hmmmed and tried to move on to non-child-related topics, but I was having none of it. What did she mean?

Could it be true: None of the stressing about sleep training or synapses or sports teams or screen time? None of the worrying about food pyramids and sugar intake and reading levels and chore charts? None of it mattered? Say what?

Her statement was baffling and mysterious, like trying to decode a hieroglyphic. I had to know more.

“Can we go back to the wasted worry thing you said earlier?” I asked her.

She kindly went on to say that, once, she actually asked her grown-up children to tell her: Of all the things that she and her husband did/said/implored/taught, what was it that actually stuck? Which of their teachings made a difference?

I leaned waaaaay in for details.

“I was surprised to hear their responses,” she continued. “It wasn’t any of the things I would have expected.”

I was practically drooling. “What did they say? What’s the secret sauce? What actually mattered!?

Just as she was about to say, a speaker stood up to begin presentations. Everyone turned their attention to him. The moment passed amid glass-clinking toasts, dinner chatter and company-purchased crab dip.

I never found out.

This, friends, is one of the great mysteries of my life. It’s the Dead Sea Scrolls. Clues in the DaVinci Code.

Messages from the Mad Hatter. Children’s inability to turn off lights.

A good friend [whose sons are both adults] once told me the sweetest, simplest thing about child-rearing I’ve heard. After a weekend spent in New York visiting his boys, having beers together in bars, laughing over dinner — even having them occasionally pick up the tab — he mooned about how amazing it was being a parent to smart, funny adults who actually want to spend time with you.

“If you do your job right,” he told me, “when all is said and done, you’ve grown yourself a friend.”

I’ve held on to that as a goal these last almost 10 years. Above all, I want my children to grow up to be free, self-sufficient, joyful contributors to society — and my friends.

I suppose I’ll have to wait until my three are grown to find out the answer to the mystery — what will make the actual difference in their lives in the long term, which values and teachings will stick, and which of the things I stress about won’t turn out to matter at all.

But just for a temperature check, I asked the twin boys and their baby sister what was resonating with them now.

Here’s what they said:

“Be nice.” “Get sleep.” “Pay attention in school and get smarter.” “Have manners.” “Be polite.”

Not one of them said, “Eat your sandwich first at lunch,” or “Wear a hat,” or “Turn.the.lights.OFF.when.you.leave.a.room!”

But that’s OK. It seems to me like we’re off to a good start growing people who will one day be our friends.

[And maybe flush the toilet too.]

Tanika Davis is a former Baltimore Sun reporter who works in communications at Constellation. She and her husband have twin 9-year-old sons, an 8-year-old daughter, a perpetually messy house and rapidly appearing gray hairs. She also needs a nap. She can be reached attanikawhite@gmail .com. Her column appears monthly.