I cracked at ToonTown.

We had been at Disneyland for just two hours and this woman was staring at my younger daughter, Sophie, who was 3 at the time.

Sophie has Down syndrome — and has always attracted attention, usually of the sidelong variety. But this was head-on.

“O.K.,” I said to my husband, Ray, through clenched teeth. “If that woman doesn’t stop staring at Sophie I’m going to walk over and tell her: Yes. She has it. Why don’t you take a picture?”

Ray looked at me, then at the woman, who was by then tending to several kids under 5.

“It doesn’t really seem to me that she’s staring at Sophie,” he said. “Anyhow, so what if she is? I always stare at people with Down syndrome.”

It’s true. He did. And so did I. Long and hard, any time I got the chance. In the checkout line at the grocery store, on the carousel at the mall. At the doctor’s office. And definitely at Disneyland.

For years, we’ve made an annual family trip there and I’ve looked forward to several things: the Peter Pan ride, a Mickey-shaped soft pretzel and some really good staring opportunities.

I’m not proud of my staring habit, but I don’t mind admitting it.

Even though about 6,000 babies with Down syndrome are born every year in the United States, and more and more people with the condition marked by an extra 21st chromosome are mainstreamed in society all the time, I just don’t see people with Down syndrome out in public on a regular basis.

Neither does Rosemarie Garland-Thomson. A professor of English and bioethics at Emory University in Atlanta, she wrote a 2009 book, “Staring: How We Look,” about why we stare at people who are different from us. She argues that people stare at people with physical and intellectual disabilities for many reasons — including to educate themselves about the unfamiliar.

“Stares are urgent efforts to make the unknown known, to render legible something that seems at first glance incomprehensible,” writes Dr. Garland-Thomson, who has a disability and has been on the receiving end of staring. Her own disability is not easy to describe, she said. “Most of the time,” she explained, “I say I just have unusual hands and arms that I’ve had since birth.”

Ultimately, Dr. Garland-Thomson told me when we talked, “what we want is for there to be so many people with disabilities out and about in the public world that we become a completely unremarkable sight.”

For now, there’s Disneyland.

On that first trip to Disneyland when Sophie was 3, my husband and I spent three solid days staring. There was only one other child at Sophie’s school with Down syndrome, and in our town in Arizona we weren’t used to seeing other people exhibiting the gait and facial features that often characterize having an extra 21st chromosome.

But Disneyland draws all kinds of people, and it seems to have a special magic for people with special needs; it’s clean, contained, accessible and fun. And there always seem to be several people there with Down syndrome. Each time I’d see someone with it, I’d immediately project into the future, and imagine Sophie becoming that person.

At the end of our trip, Sophie and I went for a final spin on the carousel.

I was so focused on getting her safely buckled in that I almost didn’t notice the woman in the navy blue windbreaker.

She was older than the others I’d seen that week, her scrunched up face with a tiny nose and almond-shaped eyes unmistakable under a tangle of dark hair. Her face was beaming with rare joy. She ran past us and I lost track of her. The ride began and Sophie squawked, then laughed. I laughed, too.

As we left the carousel, I hugged Sophie hard. I wanted to show Ray the woman in the navy windbreaker, but she was gone.

Down syndrome was still so raw and new for me. I thought about that woman for a long time after that. Somehow she made me feel like things were going to be O.K.

And they were. Every trip since, Sophie has been able to do more at Disneyland. She walked, then ran, and one fateful year she kept her pull-up dry for the whole trip in exchange for the promise of princess underpants.

I find myself staring less. I haven’t stopped — and I’m still on the lookout for other people with Down syndrome — but I don’t wonder as much about what Sophie will be like when she grows up. She’s almost there.

Oddly, I don’t mind as much anymore when I can catch people staring at her.

But for some perspective on the etiquette of staring, I checked in with Lizzie Post, co-president of the Emily Post Institute, based in Burlington, Vt.

“Most of us really don’t like it,” Ms. Post said of staring. “Why is this stranger giving me so much attention?”

Ms. Post graciously said she understood why I did it — and still do, sometimes.

“Obviously we’re humans, we pay attention to each other,” she said, adding that she considers me more an observer than a starer. But she cautioned that it’s tough for others to tell the difference and advised becoming a “sneaky starer,” or, instead of lurking in the background, approaching the person and starting a conversation.

Not long ago, I did just that.

On a visit to Disneyland just shy of her 13th birthday, Sophie rode Space Mountain twice, although I’m pretty sure the Winnie the Pooh ride was still really her favorite.

Just before we left the park, we had one last meal at the Golden Horseshoe in Frontierland, a place that serves chicken strips and loud bluegrass music. We all had our hands over our ears as we waited for our food, shoved elbow-to-elbow with other tourists.

It took me a while to notice the family next to us: mom, dad, two girls. The younger girl had Down syndrome.

I recognized the expression on the mom’s face. She wasn’t looking at me. She was staring at Sophie.

We exchanged shy hellos and smiles, and within a few minutes I learned the little girl was 5, that she could run, jump and climb but didn’t speak, that her mother worried about her and her future — the future of everyone in the family — all the time.

I stood and stuck out my hand, introducing myself. I didn’t catch the mom’s name, but I heard the little girl’s.

It was Sophie.

On the other side of the table, Ray was gathering our garbage. As we stepped out into the bright day I turned to him and asked, “Wasn’t it crazy how much that little girl looked like our Sophie?”

“What little girl?” he replied.

I smiled into the sunshine as we headed out of the park for the long drive home.