Every so often I think, ‘And so this is joy’. Not just happiness, but flat-out euphoria.

It happened this past weekend at the Lakeview School Halloween Party. It happened several times on our recent cruise. Sometimes we see it coming, other times it’s a surprise, but each time it’s like a revelation.

Our daughter is nonverbal. This presents a challenge, because we have to intuit what’s bothering her, whether hunger or boredom or discomfort. Other times, when she’s contented, there’s less urgency in figuring out the cause. Sometimes we’re just relieved, while at others she passes her own pleasure on to us.

But recently, seeing her filled with joy, I wanted to know.

In a simple state of happiness, her eyes grow wide. She might form kisses or click or make other gleeful sounds. She’ll grab her bib if she’s recently eaten, or a fistful of her shirt.

There are lots of things that make her happy.

Gabriella loves to be in motion. This can be as insignificant as rolling her around our house, sliding through doorways and between furniture, or it can involve getting outside, pushing her wheelchair up sidewalks and along the blacktop, each of us enjoying both the bumps and the flat stretches. She doesn’t care whether the air is still or the wind is whipping off the beach up onto the boardwalk so that her lightweight poncho flops over and covers her face. Scooting through the mall or lapping the running track on a cruise ship, she takes pleasure.

She shows her happiness as well when we answer her call on the monitor and come downstairs to get her changed and dressed and ready for the day, perhaps from the satisfaction that we understood her.

When Gabriella is happy, those around her are as well. It’s difficult even after all these years not to smile when she clicks. Her pleasure when on the move, her satisfaction at being understood, her enjoyment of simple attention, all are contagious.

But these are instances of happiness. Rarer, but not rare, are those moments of pure joy.

Music brings our daughter joy. Often she is ensconced in her noise-reducing headphones and so hears only a fraction of the harmonic sounds being created, but for her it’s enough. It happened on the cruise, when we packed into the back of a shipboard bar to listen to a piano player while a raucous crowd sang along. I saw it Saturday at the Halloween party, with the DJ blaring tunes.

In each case, Gabriella took in an experience combining unusual sights and sounds, as if the combination of sensations amped up her emotions. Perhaps having Lisa or me or both of us at her side helped as well. Whatever the cause, her eyebrows arched, her fists clenched, her mouth contorted and emitted an ecstasy that seemed beyond her control.

Time in the swimming pool brings a similar reaction. She loves the feelings of the warm water lapping against her, of me holding her safe with her neck and head above the surface. She drinks in the sounds around us, sea gulls calling or a fountain running or the shouts of other bathers.

I have wondered at times if the sensations might be too much for her to process, whether they could even lead to seizures, to which she is prone. But they have not, as if touching another part of her brain, as if she controls more than we suspect.

In these moments, so near to her as she inflates with emotion, I am overcome.

But it’s not only her jubilation that’s resonating through me.

I have known sheer joy in my own life – our wedding, the thumbs-up our son made during the Level II ultrasound and his subsequent birth free of the anxieties of Gabriella’s arrival, other events and milestones – but I’ve never stopped to consider them. But in these instants when Gabriella is overcome with exuberance, I feel a thrill of my own, a surge, a delight.

And so this is joy.