“You’ve never been here before!” my mom exclaims as we head down the hallway of the dementia unit where she lives. She’s talking like she’s excited to show me the place for the first time (or more likely, thrilled to discover it with me, because it probably seems new to her as well).

“Sure, I’ve been here, Mom,” I say. “At least 30 times.”

“Thirty times?” A surprised look comes over her face.

“Yes, Mom.”

That’s 30 or more trips to the Hebrew Home from Brooklyn. Thirty or more times when I take a subway to a subway to a bus and back again, two hours each way, at least once every weekend. Thirty or more times of walking the halls with my mom, and if I’m lucky and she agrees, taking her off the unit so we can visit the main floor to see the birds and the fishes, the cafe, and the sculpture garden where we might walk along the path by the river.

“I’ve never seen this before!” she always says once we step off the elevator. Because it’s brand new to her every time. But for me, it’s getting old.

“It’s beautiful here,” my mom says, and I can’t disagree. Especially on these 80-degree late spring afternoons when the sky is a cloudless and crystal clear blue and the air is soft and warm. When we return to her unit, she is like someone coming home from a rejuvenating vacation, who wants to share her experience with everyone.

“Hey, do you know it’s beautiful here?” she asks another resident, lightly caressing her arm.

“Your mother is always smiling,” one of the nurses tells me.

And I’m so thankful for these days and so thankful that her disease, while robbing her, is doing it gently.

But as grateful as I am, I’m weary.

The landscape at Hebrew Home, however expansive it may be when compared to other nursing homes, is starting to confine me. I’m also feeling constrained by the shrinking dimensions of her brain. There are so many things we can’t talk about now, so much that is out of our conversational reach. It will only get worse.

I feel guilty for feeling this way, and so I try to counter the feeling by summoning my gratitude for whatever environmental, biochemical, or universal force that is making her a happy Alzheimer’s patient.

But then on my way out, I meet another happy Alzheimer’s patient, a woman I’ve seen regularly on the unit for the past seven months. In every encounter, she’s pleasant and smiling and wishing me a nice day. Not today, though. Her face is seriously distressed; she is disturbed and upset and demanding to be taken to a room that doesn’t exist.

It stops me in my tracks.

“Oh, shit,” I think. “Happiness can stop on a dime with this disease.”

What if that happens to my mom?