What is it about us parents and firsts?

Firstborn Son has one baby book, a scrapbook and a calendar crammed full of notes: his first smile (two weeks old, and no, he wasn’t gassy); the first time he turned over (5 months); first steps (downstairs in the dining room, at 13 months.)

Each book is filled with pictures and detailed captions, including the first gift he ever received, his first visitors at the hospital, and the first time he slept through the night (alas, not until his 12th week.) Later entries include a lock of his hair from his first haircut, pictures from his first trip to the L.A. Zoo, a whole paragraph on the day he first recognized himself in the mirror. (He smiled.)

First things are exciting, worth noting, memorable. With my first two babies, I was manic about documenting everything: first words, first bath in the baby tub, first baby sign, first time he sang a song (“E-I-E-I-O” counts, right?)

My husband was just a meticulous about these little milestones. His weapons of choice have evolved from his trusty Canon and video camera to his cellphone, all within easy reach at all times, ready to capture Baby’s every move.

“Look at how well he’s holding that baby ball!” he marveled. “He’s going to be a basketball player!”

We greeted each baby feat with cheers befitting the Second Coming, with loud congratulations and rejoicing. Sometimes, we even called the grandparents for a live report.

Firstborn Son’s firsts were ours too, after all. We were thrilled and grateful and moved beyond belief that this roly-poly creature was ours and capable of yawning and finding his feet.

I remember staring at my seven-month-old as he grabbed a fistful of his hair and yanked. He yelped, outraged, for a moment, and then he did it again. He used to rub his feet together like a cricket when he was excited or happy.

The first time we spent the day at the Huntington Library in San Marino, Firstborn Son’s eyes widened in amazement when the spring breeze tickled his face. He turned to listen to the birds in the trees, the sprinklers turning on and the crunch of twigs and gravel on the garden paths as our stroller meandered through. He stared for what seemed like hours at the grape arbor near the rose garden.

I remember these firsts because I wrote them down, too photos, pressed that “Record” button.

Wonder Boy has his own photo-crammed album and memory books, but admittedly, he has less solos and more photos with Big Brother.

By the time Cheeky Baby came along, I was determined to be just as vigilant with her firsts. But my motivation was less about posterity, and more because I was 40 and already earning an impressive reputation for short term memory loss.

And for everything I document, I know I’m celebrating an achievement of sorts, but also a farewell, for with that first word (it was “up” for the boys, and “Papa” for Cheeky), we are leaving behind sweet babyhood, as triple-roll thighs give way to sturdy toddler legs. Moments like this slip away every day, minute by minute.

I’m now the mom of two teenagers and a 10-year-old, and I’ve marked off the first driving lesson, the first heartbreak, a first job (a happy summer working at Potato Corner in the mall.)

The firsts keep coming, and none last forever.

It’s as it should be.