Next week our son, William, will start Kindergarten, and though he’s been in preschool and has had his fair share of babysitters, I know this drop-off will be different.

I look at William, modeling his new school clothes to make sure they fit and then asking if he can wear them to bed, and I can’t believe he is the same loaf-of-bread-sized terrorist who kept us awake for the first year of his life, then whined and kicked through the subsequent two.

Is this the same person who puked all over his new rug and pooped in the bathtub? This person, who can now open the refrigerator door by himself and—Praise God almighty!—get the ketchup for his hot dog. This person who makes small talk with our neighbors and dribbles a basketball better than I can. Where did this creature, this human being, come from?

Now when William sits beside me on the couch, as he did yesterday, his long limbs sprawling in every direction as he quietly read a book and I perused the newspaper, his sister napping in the other room, I can barely hold back the tears.

I remember taking him to a neighborhood café on an August morning three years ago. He was two and a half, a bundle of spastic toddler energy. We got our food and careened to a table, where I knew we’d have about three minutes to wolf down our scones before skulking away, the stares of laptop-brandishing grad students willing us, in all our messy loudness, to get out. I groaned inwardly at the long day ahead.

And then I saw her—a casually dressed mom at a nearby table with her shaggy-haired, eight-year-old son. They were eating muffins without the fever of caged animals, and talking without throwing Puffins at each other. She didn’t have a trace of food or snot smeared on her shirt. What lovely creatures were these? I wanted more than anything to fast forward my life to then.

And, now I’m there—or nearly. I’m not saying life is all bliss and summer afternoon reveries. But the sheer physical caretaking of William has subsided (and his younger sister is coming along quickly), and the real meat of our relationship—the conversations, the thoughtful exploration of ideas, the oft-reciprocated empathy—is finally taking off. Somehow, I’ve managed to get through the first five years of motherhood with my sanity, if not always my dignity, intact. And I know that surviving those hard days, which also included gummy smiles and drool-laced laughs, melted something inside me and my husband and knit us together as a family.

Now I see moms of babies along our busy city street, and they look as stressed out as I remember feeling: Chasing down a bottle flung from a moving stroller like a shot over the bow. Heaving a crying baby onto a shoulder at a restaurant and trying to eat with the free hand. Grimacing through the humiliation of a grocery store meltdown.

And I want to tell them what I’ve learned in these years leading up to my son’s first day of Kindergarten. It’s the wisdom that older women on our street have been trying to convey to me all along, though it’s taken me five years to slow down enough to hear it: That one day, you too will sit with your sons and daughters on the couch, like old friends, silently enjoying each other’s company. And one day not so long after that, they will leave you.

“Enjoy him,” the old women have been saying to me for the past five years, pointing their crooked fingers at the baby boy who is now four feet tall.

“He’ll grow up fast.”

Katherine Ozment is a Glam Family contributing editor, and a freelance writer working on her first book. Her essays about motherhood have been widely published and can be found at www.katherineozment.com. She lives in Cambridge, Massachusetts, with her husband and two kids.