I can’t imagine Harry Potter with gray hair.

Or wrinkles.

Or jowls, or any of the other obvious physical evidence of the inevitable, incremental effects of aging.

Harry, of course, is a fictional character, and so immune to such signs of impending infirmity.

But he, along with his mates Hermione Granger and Ronald Weasley, also is a fictional character who made the great leap from ink on a page to high-definition on a movie screen.

And no matter how rich and compelling the world that author J.K. Rowling coaxed from her imagination — and it’s more vivid than most, in my view — prose can’t compete with the immediacy of actual people playing roles.

Moreover, that trio, and the many other characters who populate Rowling’s fantastical and fabulous tales, portrayed their characters over a series of eight movies spanning a decade, 2001 to 2011.

And actors actually age.

The progression of years is especially noticeable when the decade in question includes the teenage years and the transition from child to adulthood.

Rarely, though, have so many people around the world watched a group of actors make their way through adolescence and beyond.

But then rarely has a writer pulled off an achievement as epic as that wrought by Rowling.

I passed a couple of quite pleasant hours on a recent afternoon watching many of those actors talk about the legacy of the Harry Potter saga.

They laughed often.

A few times they wiped tears from their cheeks. And I’m quite sure these were real tears rather than the feigned emotion that actors can summon (sometimes with the aid of carefully placed eye drops).

This documentary was prompted by the 20th anniversary of the release of the first of the eight films, “Harry Potter and the Sorcerer’s Stone.”

(Rowling actually wrote seven books. But the final installment, “Harry Potter and the Deathly Hallows,” was divided into two films, the latter released in 2011.)

Although I greatly enjoyed each of the movies — if not so much as I did Rowling’s novels — I was nonetheless surprised by how powerful was the nostalgia I felt while watching the 20th anniversary show.

I suspect this had something to do with seeing, as adults, these actors who, in many cases, I remember only as children and whose subsequent careers I know little about.

The documentary is thorough, to be sure, featuring interviews from more than a dozen actors who had prominent roles in the franchise.

But naturally the emphasis was on the trio whose friendship weaves the strongest thread through the series — Harry, played by Daniel Radcliffe (who’s now 32), Hermione, portrayed by Emma Watson (31), and Ron, played by Rupert Grint (33).

The most poignant moments were those in which these three actors talked about how the unique experience they shared also forged between them a bond which will last the rest of their days.

It could hardly be otherwise, it seems to me.

During the period of life that is so instrumental in determining a person’s future — from about age 12 to the early 20s — this trio not only spent hundreds of hours together, but they did so in the intimate atmosphere of a film set while making some of the more beloved movies in history.

Few of us become world famous during our teenage years. We can hardly conceive of the experience, so foreign it is to our own.

I was struck by how many of the actors talked not of fame, however, but of how grateful they were to have had the chance to contribute to something that has delighted so many people across the world and across nearly the whole of the age spectrum.

I suppose I ought not be surprised, though, particularly that Radcliffe, Watson and Grint would feel that way.

They could hardly have known, when they started on such a great adventure while still children, how the 10-year span would affect them while it was happening, nor how it affects them still.

Yet as much as I enjoyed watching these actors again, this time following their hearts rather than a script, as much as I relished reliving some of my favorite scenes from the films, my overriding thought wasn’t of movies but of books.

Almost none of us, after all, would today recognize the name Harry Potter — or Daniel Radcliffe, come to that — had Rowling never written about the world she conceived in her mind.

And I believe our world would be a lesser place in the absence of these stories and these characters.

I don’t know if the magic that Rowling created will be replicated. Such things are rare, and all the more special for being so uncommon. Certainly no other series of novels and films in this century is so celebrated, or beloved.

And as much as I appreciate the films, and was entranced by seeing in real life (albeit a cinematic version of real life) the places and people who until then lived only in my mind, if I had to choose only one format that I could have for the rest of my life I would choose the books without a shred of regret.

This, I think, is by far the greatest of Rowling’s achievements — to instill in multiple generations the inimitable experience of reading about a world so vivid that it comes to seem, in those irreplaceable hours spent looking at the pages, as real as the one we temporarily leave to its own devices.

Jayson Jacoby is editor of the Baker City Herald.