As my girlfriend and I walked out of DC's E Street Cinema on Sunday afternoon, the biggest line I've ever seen in an art-house theater had formed in the lobby. She saw someone she knew and asked what they were waiting for. "Boyhood," they replied, confirming our suspicions and also cementing that this little film is already on its way to becoming a sensation.

You may already be familiar with its origins; filmed over the course of 12 real-life years, Boyhood follows the maturation of Mason (Ellar Coltrane) from small child to young man. Richard Linklater, the writer/director, met up with his cast members once a year to discuss new scenes and determine where Mason and the rest of his family might be at that particular point in time. His divorced parents Olivia (Patricia Arquette) and Mason Sr. (Ethan Hawke) are constant presences, as is his sister (Lorelai Linklater), but almost everyone else comes and goes with the ebb and flow of life.

Linklater pursues realism over manufactured drama; moments that seem destined for a tragic end (boys messing around with sharp objects in a house under construction; a step-father who drinks too much) simply grind to a halt and then fade away. The scars are emotional; not physical. Mason never suffers serious harm at the hands of anyone, but as time passes you can see how dribs and drabs of negativity shape the person he becomes.

Because the line between Mason and Coltrane is intentionally blurred, it's hard to tell how good of an actor he might be. But even if he's never in another movie, he's brilliant at inhabiting this on-screen persona that grew so naturally over the course of the film's 12 years. Everything he does feels organic and honest, and the evolution of his character traits belies what must've been an intense collaboration between young Coltrane and his director: Mason's greater ease at accepting Olivia's poor choices in relationships or Mason Sr's inability to commit to fatherhood seem to reflect an increasing comfortability with both Arquette and Hawke as Coltrane went from little kid to mature teenager.

Boyhood meanders at times; it's not plot-driven so more than a few threads are left twisting in the wind. I understand what Linklater is going for here (again, realism over drama) and I'm not a stickler for traditional plots with spelled-out resolution, but stories are told a certain way for a reason. And sometimes the shots or dialogue that establish the year feel a little forced; a lingering shot on a Game Boy Advance SP does make me stop and wonder when the handheld gaming device came out, but that bit of context doesn't necessarily provide enhanced cinematic enjoyment.

At the same time, Linklater's filming style allows otherwise stilted bits of dialogue to ring true. Mason raises some traditionally weed-induced philosophical queries that must've sounded lame as heck on paper, but that's also the point. Very few people are wise or relevant at age 18; the topics my friends and I were talking about back then certainly weren't taking seriously. Mason is introspective and not afraid to speak his mind when comfortable; the takeaway of these scenes is not the content of his mini-rants but who he's saying them to, and how he's gotten to this point in his life.

And the 165-minute runtime, which may scare some viewers away, is hardly an impediment. I'm usually a big proponent of a nice trim film (one of my favorite post-theater comments is "They could've cut 10 minutes," and they usually could've) but to fully tell Mason's story in the manner Linklater has chosen, you need every moment. Perhaps the most accurate way to describe my feelings on Boyhood is to note that I usually respectfully ignore films made in such a slow, indirect style, but this one hooked me.

It's hard not to wonder if knowing the backstory adds to the drama; would I have been as invested if I thought Linklater had cast three brilliant, nearly identical kids of different ages? That said, the joy of a good cinematic experience is a film touching you in its own way, with whatever mood or perspective you bring into the theater that day. And as Boyhood wrapped and we left Mason right on the verge of becoming a man, a few tears were flowing. Not tears of sadness or even happiness; just the end result of a deep emotional investment brought about by one of the more unique films I've seen in quite a while.