A neighbor stoops to pet my dog (our dog, the littlest of our three), greeting him by name.

It is a cool, but not chilly, late fall afternoon, children playing in their yards, lights beginning to turn on behind windows, streets laced with dog walkers out for a pre-dinner stroll.

One of the children, a young girl, runs over and asks if she can pet the little dog, but the neighbor stops her. “He’s not always friendly,” the neighbor says, though he uses the dog’s proper name when he says this.

He knows, this neighbor, that this child will listen to him, and he is right to discourage her. The little dog has shown his unpredictability. I counter that she is welcome to pet one of the big dogs, who are nose-down in leaves, sniffing for cat poop and wagging their tails. The girl skips back to her friends.

How is your dog? I ask my neighbor, though of course I don’t say “your dog.”

He’s gone, several months now. Eaten up with cancer, my neighbor says. I wonder how this is possible, then realize how long it has been since we’ve run into one another this way, casually walking the block.

I start to respond, to say what a good dog and how much they must miss him, but another neighbor, one I’ve just met, shoots me a look and changes the subject. The wound is still tender. We talk about babies and football and autumn leaves instead.

Eventually, the dogs become restless and signal that it’s time to keep moving. We say our farewells and Happy Thankgsivings, and the dogs and I finish circling the block, climb our front stairs, walk around back to deposit the bag of stinky stuff in its dedicated bin. I unclip the leashes, and we head indoors, the dogs and I, as if there had been no interruption in our once-familiar routine.

A few weeks later I am out, alone, on a Saturday. As I’m crossing the street, I see something moving, just outside my direct line of sight, behind and off to the side. It’s a neighbor, a different one, walking her dog and waving. I turn around, trot back to her, pause the sounds piping into my ear (this is more clumsy than it sounds) to say hello and fall in stride.

Don’t stop for me, she says. You had a good pace, and I didn’t want to stop you, just wanted to say good morning, she says.

We walk a block together and talk. Child home from college, child heading to college, work, spouses, the weather. She rounds the corner to head home; I turn the other direction, pull the phone from my pocket, press “play,” and pick up where I left off.

I’ve thought about this alternately as a comeback tale (A Return from Knee Injury!) or a dog story (Our Unfailingly Loyal 4-Legged Friends!), with variations ranging from humorous to wistful, and things in between.

This gist of it, I suppose, is that after nine months of rest and relative inactivity there are days, now, when I forget all about the bit of torn stuff in my knee, that merit badge of middle age, acquired on a tennis court playing doubles with my son last spring.

In that moment, in its direct aftermath, my first thought was of how long it would take to get back to normal. Then, realizing this would be a slow process, I began to fill the days with other things, while the once-normal things kept on moving without me.

I’ve missed playing tennis with my son, who next Christmas will be the one coming home from college. I’ve missed walking with my dogs, who are terrible but also unfailingly loyal and loving and delighted to walk around the block, whenever that happens, or to sit with me on the sofa whenever it doesn’t. I’ve missed seeing neighbors while out walking, the small milestones that distinguish one day from another, blurring larger changes underway.

As my husband is fond of saying: The time is now.

Running Christmas errands with my daughter I run into an old friend whom I haven’t seen in ages. After friendly greeting and hugs, he stops, awestruck, to take in the sight of the two of us. He pulls off his hat, ruffles his silver hair. My god, he says, look at us! Look at her! It’s unbelievable!

She’s driving, I tell him, all on her own now. He is amazed. It’s his first Christmas without his mother, I remember, and he nods and smiles and says something both kind and irreverent.

On the way home my girl and I run through the list of things we need to do before my sister arrives for our first Christmas together since our mother died, 14 years ago.

We have cookie dough in the freezer, wine in the basement, fresh sheets ready to go on beds. We’ll make a grocery run, tidy up, doing the things that are there to be done, aware of things that cannot be known.

Here we are.