Richard Linklater has a talent for time—or at least for gauging its passage.

Born in East Texas 54 years ago next week, the writer-director virtually invented the American indie flick with his Slacker, shot in 1990 on 16mm and a toy PixelVision camera. He followed that up with Dazed and Confused, the apotheosis of stoner-teen comedies, as well as a launching pad for the careers of Ben Affleck, Milla Jovovich, and Matthew McConaughey.

Since then, he has veered between offbeat experiments like Bernie and the animated Waking Life and ingratiating family fare such as School of Rock and the Bad News Bears remake. (Linklater now says he made those so his then-small children could see what he does.) Without taking anything away from those accomplishments, the heartbreakingly personal, gently witty Boyhood kind of sweeps that deck clean.

In the nearly three-hour effort, opening Friday (July 25), a Texan called Mason, played by newcomer Ellar Coltrane (the kid chose to go with his jazzy middle name), grows from a chubby kindergartner into charismatic young adulthood right before your eyes, without the benefit of makeup, CGI, or midgame substitutions.

To launch this ambitious project, Linklater engaged a small band of actors who agreed to shoot for just a few days every year for 12 years. Ethan Hawke, who proved his loyalty and stamina by playing the same character in Linklater’s Before Sunrise and its two sequels, at nine-year intervals, would be the peripatetic dad. And Patricia Arquette, only 34 in 2002 and on a career roll, would play the college-student mom. Their characters have already divorced even before we meet Mason and his slightly older sister, played by Lorelei Linklater, the director’s oldest daughter, now 21.

“I’m so proud of her,” says the veteran filmmaker, calling the Straight from New York City. “She was convincingly annoying in the early scenes, but you have to remember: this is all from the point of view of the little brother. I had two older sisters myself, and we eventually started realizing we were all on the same team. As a kid, though, siblings are just in your face, in your room; everything’s a ground war, or at least a border skirmish.”

The contours of Linklater’s own bumpy childhood seem to be visible in Mason’s coming-of-age journey.

“Certainly, I updated some of my own experiences. But in film, you get an extra layer of distance, because even if you’re trying to do something that’s spot-on autobiographical, after you start working with your actors, you begin deepening the material with their experiences; then it’s open to more layers of interpretation. It may move a step or more further away from your own life, but it also can be more compelling and real because of it.”

It’s one thing to get your whole crew on the same page for a single event, but isn’t it risky when those pages are spread over a dozen years?

“You mean something might happen to one of your main actors?” Linklater asks. “Sure, or they might not want to carry on the project. I always allowed for that. But the way it actually happened turned out to be very novelistic. It almost didn’t feel like a film, because the working methodology was so different. To be able to film, edit, attach that material to whatever else I’d already shot, and then have a year to think—I mean, with most films, you do all your thinking upfront, then you’re in production, and then you’re just hanging on for dear life, trying to remember why you started this thing in the first place.”

Of course, the Austin-based director was working on other projects—roughly a dozen of them—the entire time this proceeded.

“It was pretty much a swirl of all the above, with that generous hunk of time to think about what this one story really needs. And it never happened that someone wasn’t available. You know, Ellar was actually the most constant element, and the most reassuring. He lives in the same town as Lorelei and me, but Ethan and Patricia were just constantly working. We were everyone’s side project, but everyone was passionate about it, too, and really committed.”

In practice, that meant Boyhood became a safe place for its participants to go, year after year.

“A lot of people jump on that idea that ‘It’s like going to war, you’re fighting against the elements,’ and all that. But I always thought filmmaking should be a more natural extension of your ideas, of the stories you want to tell. Sure, you have to work hard and plan carefully, but it doesn’t have to be hell.

“I guess I’m trying to get at the heart of the human reality, and it’s fair to say that I’m from the naturalist school. But every tale has its own needs and desires, and you have to acknowledge that it’s all a construct. This thing I’m going for that’s supposed to feel real is highly thought-out, highly rehearsed, and highly manipulated. I don’t want the audience to be moved by a certain style or mood, but by the reality of the people they’re encountering.”

This particular reality is that of a young white male getting gradually drawn into a culture increasingly unsure of its own dominance.

“There’s all this advice coming at you when you’re a boy. ‘Stand up straight, get a haircut, get a job, be a man!’ Again, from a boy’s POV, everyone’s trying to mould you, protect you, change you—all for the future. You’re being groomed to be something else, and you’re not sure what.”

Whew! If you’re a parent, especially the male kind, you’ll probably wish you could have seen Boyhood before undertaking such a big task.

“Me too,” Linklater responds, with a too-knowing laugh. “If I knew then… Of course, parents are drawing on this huge body of knowledge, but it all depends on how you understand that history—whether it becomes a burden or a blessing for your children.”

And speaking of history, it’s exceedingly rare to find absolutely no anachronisms in a story set in the past. And this is yet another unique aspect of Boyhood.

“We filmed a period piece in the present tense,” the director declares, with something resembling pride. “And you don’t get that opportunity very often. You try to keep it simple and timeless, but at the same time you’re keeping an eye out for the detail you just know will be funny 12 or so years in the future. Songs, video games, clothes. That’s why I filmed that big, turquoise iMac in profile. When that computer was new, I took one look at it and thought, ‘Wow, that thing’s not long for this world!’ ”