In the ninth century, the Catholic Church announced that the remains of the apostle James had been discovered in the far western reach of the Iberian Peninsula, at what would become the town of Santiago de Compostela. It further declared that anyone willing to make a pilgrimage to the spot would receive plenary indulgences, or the remission of punishment for their sins. The faithful came running, er, walking. The Camino de Santiago sprang into existence and has been traversed, with varying degrees of popularity, ever since.

The Camino passes over the Pyrenees Mountains and bisects desolate plains; it leads through villages of a few dozen inhabitants and sizable cities (Pamplona, León). Often under blistering sun.

I first walked this path a quarter-century ago. There was no religious call to my walk, but like so many pilgrims through the ages, the Camino produced in me a transformative — dare I say spiritual? — experience. I’d always wanted to return to the Camino and in the summer of 2021, I invited my then 19-year-old son, Sam McCarthy, to join me. Sam, an actor and a native New Yorker who has appeared in such shows as “Dead to Me” on Netflix, surprised me by saying yes. We arrived in Spain in late July and walked through a scorching August to Santiago de Compostela. And then, while I sat my weary body down, Sam continued on, for 50 more miles to the sea, ending his journey in the village of Finisterre.

I’ve written a book, “Walking With Sam: A Father, a Son, and Five Hundred Miles Across Spain,” that tells the story of our journey from my perspective, but what did it mean for him? Why would a teenager say yes to a month of walking with his father?

“It didn’t really feel like a big decision,” said Sam. “It was something you’d always talked about, and it intrigued me — the idea of walking across a country. I didn’t feel like, ‘Oh, now I’m going to walk and do this thing with my dad so we can get closer.’ It wasn’t really like that for me.”

“But I’d say it did draw us closer,” I said.

“Of course,” he said.

This conversation has been condensed and edited for clarity.

What surprised you the most?

Before you set out on something like the Camino, at least for me, the idea of completing it or finishing felt kind of amorphous. I didn’t know what to expect. But there’s a great strength that comes with an achievement like doing the walk. It’s kind of unshakable. It’s a tangible thing that you completed that can’t be taken away from you. I suppose for the first time I gained a sense of doing something hard that had seemed a bit incomprehensible. I mean, there’s a hill and it’s so far away, and then I get to the hill, and then I walk to the top and then off in the distance there’s another and it’s super far away. And then I get to it and then I get to the top, and then there’s another till you reach somewhere. And that gives you, I don’t know, a kind of ownership that can’t be explained away.

Did you find it physically challenging?

Yes, I did. I found it difficult, physically, for the first two, two and a half weeks, and then for the last few I felt like I could walk two more countries.

Why did you go on to Finisterre?

Because what’s the point in just going to Santiago?

Because that’s where the pilgrimage ends.

Yeah, but I wasn’t a religious pilgrim. That wasn’t a thing for me. It was always talked about as a walk across Spain, and then you’re stopping 90 percent of the way? Why would I just stop?

The easy metaphor of you going beyond what I did, the idea of my son achieving more than me — I think that’s a desire lodged in every parent’s psyche.

OK, well, that’s your thing. I wanted to see the ocean.

Was arriving at the sea the highlight of your journey?

It was the whole experience. It’s kind of indescribable, and I think trying to talk about it is weird because the words in the English language can’t really — not that it was such an intergalactically profound experience, although it was profound. It’s just more like I don’t know how one would really describe it. I suppose the highlight was the state of being that you enter. And sure, reaching Finisterre, but I’m not sure finishing should be the point.

What is the point?

There was a saying on the Camino that you didn’t understand or really care about that I loved, “Walk, don’t reach.”

So what does that saying mean?

It means just walk. Don’t be thinking about where you have to be next. Don’t be grasping for a finish line. Just be here as opposed to reaching for what’s ahead in five minutes, five days, five weeks from now. It’s not an original thought. But you know, maybe I had kind of lost myself before the Camino, and I guess you saw that. People go to try to find themselves again. You walk and walk and walk and it’s like, am I over here? Am I over here? And it’s like no, I’m right here this whole time.

Mmm. Would you do it again?

Yes, yes.

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