My house smells like hyacinths. Leftovers from the flowers I bought to make a boutonniere and a corsage for my son and his girlfriend for their prom. Musky and sweet, the scent greets me when I walk towards the kitchen to make the coffee.

The flowers they did not choose to wear are arranged in a vase across from where I sit in the stillness of this early Sunday morning. The only sound indoors is the hum of the refrigerator, although the chattering of the second shift of birds is prodigious. (The first shift, far more tuneful and less demanding, was on duty before 5 a.m., and they have already quieted.)

I keep scrolling through the photos — smiling girls in dresses that ripple in the breeze, boys with ties they chose to match those dresses. Clowning poses. Lightly awkward ones. Tender ones. They have a hard time navigating stairs in these heels. They do not quite know how to wear these suits, in public, their arms around each other. And yet, oh, they do want to. The candids are breathtaking in the glow of sunlight’s golden hour, perfectly imperfect with hairs out of place and natural smiles and a closeness to each other.

The beauty of this youth — a beauty they do not even know they possess — is not about their lovely skin. It is about the depth of their eighteen-ness. It is the earnestness with which they faced their own desires for the evening. For the world.

My son had wanted a whole, proper suit, had clear ideas about the details. But as he got ready last night, he asked for my approval with every item he put on. “Is this right, mom?” and “how does this look?” and “can you button my collar?” Yearning in both directions: to be more grown up, not to have to know it all on his own. Pink shirt cuffs buttoned, flowered tie knotted, he sat down to tie his dress shoes, and I watched him hold out his hands and just look at them. They had the tiniest tremble. A pause. Yes, he said, he did want to take the flowers with him to pick up his girlfriend, but could I pin his on when I met them at the park for photos, because he didn’t think anyone else would know how.

In the park, their group of five (one poor date, home sick, missing her senior prom) is a cluster among so many clusters of glimmering joy. A mother says, “give each other a kiss.” My son looks confused, disbelieving he has heard correctly. He hesitates, says, “Here? at the same time?” He cannot imagine kissing this girl out in the open air. In the sunshine. In front of other people.

The daughter leans in, her palm brushing my son’s neck, and kisses his cheek. And the moment is everything. The involuntary way his hand gently holds her waist, the breeze catching the hem of her silky skirt, his smile as he draws her slightly closer. Everything. The warmth of the sun and sparkle of the park’s little creek, his pleasure and his shyness, the heart-fullness of witnessing his desire to do all the things right tonight. Everything. The thick tousle of his hair and the so many pictures I have taken of him monkeying around in sunshine while I reveled in the play of light on that perfect skin of childhood. The lifetime of raising a boy and suddenly feeling him on the cusp, not child not man. One exquisite drop of everything.

“Thanks, mom” he’d said, as he was leaving the house to pick her up, “for the clothes, and the flowers, and everything.” And he looked at me. And he walked out the door.

And oh, I was unprepared for eighteen to be the hardest age. The launching, and the gossamer threads of connection one can only hope, spiderweb-like, will hold with a strength their near-invisibility belies.

The scent of the hyacinths they did not wear gestures to the flowers they did. And that way lies the future. The choices, the traces, the lingering scents after they leave a room. Or a house. The lingering scents of memory. The joy, and the peculiar loss one must swallow as part of that joy, in watching your child’s becoming.

Yes, I told him, that’s right. You look wonderful.