took 12 years, in film as in life. For 12 years, director Richard Linklater shot the movie for a few weeks each summer as both the main character, a boy named Mason, and the actor, Ellar Coltrane, came of age, from 6 to 18. The epic undertaking has resulted in one of the most honest and absorbing representations of growing up ever put to film: all the tedium, all the wonder. All story, no plot.

Or maybe—judging also from Terrence Malick's The Tree of Life—growing up is just more beautiful in Texas. The sun shines more, and it's always golden hour.

Like a lot of kids, Mason is shiftless. He likes video games. He likes trampolines and bikes and, eventually, girls. You feel, through his eyes, the deep mysteries contained in his mother's Victoria's Secret catalog, and the singular injustice of having an older sister—played by Linklater's daughter, Lorelei—who is way better at lying than he is. 

We see him in a series of moments, and they blend into each other without announcement. New haircuts appear. Obama runs for president. We see a teen girl awkwardly saying that "a friend" has a crush on Mason, and then we see her as Mason's first girlfriend. It feels like memory, except we don't know how it ends.  

The passage of time amounts to a special effect more powerful than CGI. How did this wistful kid with sun in his cheeks become a lanky, zitty teen with an ill-advised mustache? And when did he get so handsome? Who bought him that skateboard? Holy shit, they're wearing Tevas and watching Dragonball Z. As in life, the moments pass naturally, effortlessly, but in their accumulation we see—with all the suddenness of epiphany—that we have changed. The realization is startling, wondrous and sad, as in Linklater's Before Sunrise trilogy, where the passage of time also shows up on the actors' faces.

At its heart, though, Boyhood is less about boyhood than parenthood. Much of the viewer's empathy lies with Patricia Arquette, who plays a mother struggling to raise two kids mostly on her own, with the occasional incursions of men. "Men" includes absentee dad Ethan Hawke, who plays Ethan Hawke.  

As in What Maisie Knew, we see these fumbling attempts at parenthood only through the eyes of the child. In one powerful scene, Mason comes home to find his mother weeping on the floor. She tells her son she slipped and fell. The stepfather, looming nearby, tells him the same. It is the film's only flirtation with melodrama, but because the situation is developed so patiently, it has the queasy, awful feeling of reality.

In Boyhood, the world of men is often either terrible or useless to children. An early shot shows the mother's very tall boyfriend from the low camera angle of a child. He looks terrifying, and not just because of his awful goatee, as he complains that Arquette couldn't find a babysitter. From a child's view, the drunken parade of suitors and stepdads do little, see only failure, and pity only themselves. And even though the love of philosopher-dad-by-weekend Ethan Hawke is palpable—beautiful, really—he doesn't learn how to be a real father until he starts a different family, with a different wife. Oh, the unfairness. 

Just as the parents grow up with the children, the film becomes increasingly aware of itself as it progresses. When Mason leaves for college, his mom suffers a breakdown. "My life is going to go," she says, "just like that, nothing more than a series of events." Mason grows up, he graduates, and now there's no more for her to do. She's written out of the movie: "You know what’s next? My funeral.” 

"Aren't you jumping ahead like 40 years?" Mason asks, in a sly wink to the audience. But we are being abandoned, too. This movie makes parents of us all, and the three hours have passed too quickly. An entire world of possibility will stretch out in front of him, but we who watched him grow will be left behind as the credits roll, grateful and a little brokenhearted. 

Critic's Grade: A

SEE IT: Boyhood is rated R. It opens Friday at Cinema 21.