The last thing my 10-year-old asked me last night was if he'd get his seal shirt in the morning. The first thing my 11-year-old mumbled when I turned on his light and wished him a happy birthday was, "Seal shirt."

His obsession with seals started with his first stuffed animal, a harbor seal that was a cast-off from his sister's collection. Petey is the go-to for not just bedtime, but is also well-traveled and part of the headcount on trips, leaving hotel rooms, and is best strapped to me at the airport, just in case.

I have panicked about Petey one too many times.

And yet, as a millennial who appreciates a good fandom and who has gone through a whole wardrobe of wacky shirts with sayings, like the classic question, "Would a city built on rock and roll be structurally unsound?" I figured I'd amuse myself by buying him shirts with seals for his birthday. One has a seal with sunglasses and the phrase, "I'm kind of a big seal." Another has a seal and the words, "Seals are awesome. I'm awesome. Therefore, I must be a seal."

One of my favorites is a seal with a word bubble saying, "Nice."

Its caption: "Seal of Approval."

He must be my child because every year he's happily anticipated and worn them. However, there did seem to be a limit to the internet, and the searches for strange, child-sized seal shirts started to wear a little thin. I thought this year we could switch it up. He started the hobby of chess last year and has developed a semblance of obsession. Not seal level, but solidly enjoying chess. A chess shirt?

In a pre-bed doomscroll, I flicked over to another app and typed, "Seal playing chess."

Wouldn't you know it. Of course there was. Chalk up a win, internet. Way to support the millennial mom with the weird humor.

So this morning, there it was waiting for him: a seal sitting over a chessboard. The tradition survived another year.

There are traditions we inherit and traditions we deliberately establish, the same Christmas ornaments or the beach we return to every summer. Then there are the ones that sneak up on us. Nobody decided that my son's birthday would require increasingly obscure seal apparel. A discarded stuffed animal became Petey, Petey became an obsession, an obsession became a joke, and somehow the joke became something a ten-year-old thought about before falling asleep on the last night he would ever be ten.

A birthday is an arbitrary square on the calendar until someone you love arrives on it. Then you return to that square every year, measuring the distance traveled since the last time around. Toys disappear from the bedroom and you buy larger sizes of shirts.

Earlier this week, I packed up another round of too-small clothes, old toys, and costumes for donation, a task that gets more emotionally hazardous as my kids get older. In the pile was my daughter's old pink, glossy superhero cape.

I remember that cape because I remember the picture. She put it on when she was little and, instead of simply smiling for me, struck a superhero pose. It's still one of my favorite pictures of her, not because of the cape, but because I remember recognizing something in her that day. Her humor was becoming her own. She knew she was being funny.

This is the strange archaeology of raising children. You don't know which objects will become artifacts until suddenly you're holding one. A hand-me-down stuffed seal becomes an essential traveling companion. A joke becomes an annual birthday shirt. A cheap pink cape becomes evidence of the moment you first glimpsed the person your child was becoming.

I don't need the cape to remember the girl inside it, and I don't need to save every seal shirt my son outgrows. Some other kid gets to put on that glossy pink cape now and discover their own superhero pose. That's what objects are supposed to do. They move through our lives.

The meaning stays behind.

Someday Petey may finally retire from active duty. Someday my searches for seal shirts may end, not because the internet finally runs out of them, but because my son stops asking.

Today was not that day.

Cassie McClure is a writer, millennial, and unapologetic fan of the Oxford comma. She can be contacted at [email protected]. To learn more about Cassie McClure and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

Photo credit: Vanessa Bucceri at Unsplash