It's a travesty that Boyhood didn't win Best Picture. I saw it five months ago, and I'm still thinking about it, in part for an unusual reason: it might be the best movie ever made about going to college in America.

Boyhood, shot over 12 years, is about a kid named Mason (played by Ellar Coltrane) growing up and going to college. It's a beautiful narrative about childhood, parenthood, and the passage of time. But it also contains a surprisingly nuanced portrait of higher education and the roles we expect it to play in our lives.

Americans expect a lot from college. College is seen as the best, maybe the last, engine of social mobility. But in the popular imagination, it's also where you become an adult — a place not just to get a degree, but to drink illicitly at parties and hook up in dorm-room beds, cheer for a football team or sing in an a capella group.

Those two ideas — college as an economic imperative and college as a coming-of-age journey — are barely related. But they're routinely mixed up, because what people think of as "college" is so defined by their own experience. Policymakers talk about the value of college for social mobility and economic growth, and the audience imagines teenagers and leafy quads and fraternity houses. This has serious implications. It's hard to shape a sensible higher education policy if you can't answer the central question: "What is college for?"

Boyhood doesn't give one answer to that question. It gives many — and by doing so, it shows how our ideas about higher education can get so confused.

Boyhood and the social mobility narrative

A decision to go to college sets Boyhood's entire plot in motion, and it's a decision mostly about the economic benefits. A few minutes into the film, Olivia (Patricia Arquette), a single mother, tells her two children that they're moving to Houston so she can finish her degree. "I have to go back to college so I can make us a better living," she says. "With this job, I can't take care of us the way I'd like to."

We see her a few scenes, and a few years, later, in a classroom at the University of Houston, Mason sitting next to her. (He's sick and not in school that day.) They both look a little out of place: a youngish mom in a blazer and a 9-year-old boy in a sea of undergraduates in tank tops.

Olivia's experience is far more typical than you might realize

If this were the only mention of college in the movie, Boyhood would still be an achievement. Hollywood's version of college doesn't usually feature striving single mothers who struggle to find childcare and are in college because they want a better job. But Olivia's experience is far more typical than you might realize. One-fourth of all American college students are women older than 25. Like Olivia, about 25 percent of college students have children.

Boyhood gives us other glimpses of college students who don't fit the typical Hollywood mold, including a veteran of the Iraq War on the GI Bill. (About 1 million veterans of the Iraq and Afghanistan wars have used those tuition benefits.) Olivia earns not only a bachelor's but a master's degree, and she becomes a professor. In one scene, she urges a young man repairing her septic system to go back to school, no matter what he has to do: "Go to night school. Go to community college — it's affordable." That's a message about getting ahead, not about growing up.

Olivia's academic path, going from a working mom trying juggle classwork to a college professor giving a confident lecture, is a triumph. (It also, it must be said, strains the movie's realism a little; in real life, she'd need a Ph.D.) Her story is something a politician could insert straight into a speech about the importance of going back to college. It's the social mobility narrative of higher education in its perfect form.

Boyhood, college, and coming of age

Boyhood started with someone headed to college, and it ends that way, too: Mason drives across Texas by himself, moves into a dorm at Sul Ross State University, and blows off an orientation session to take drugs and go hiking with his new roommate.

By this point, it's already been made clear that Mason's expectations for college are different from his mother's. On a trip to the University of Texas at Austin while in high school, he and his girlfriend hang out at a bar, eat late-night queso at a diner, and get naked in a twin bed after sunrise. "By next summer, this'll just be our lives," Mason says. "Staying out all night, going to shows, whatever we want." For his mother, college was about social mobility; for Mason, it's about coming of age.

Or at least he thinks it's supposed to be. "I'm not counting on it being such a big transformative experience," Mason says. "Look at my mom. She got her degree and got a pretty good job… I mean, basically, she's still just as fucking confused as I am."

Those few lines of dialogue show the giant contradictions in how we think about college. Boyhood started with Olivia saying she wanted a college degree so she could get a better job and take care of her family. And now she's a college professor with a mortgage, a daughter in college, and a son on the way there. That's amazing. It's exactly what she said she wanted. For Mason, it's just a baseline.

That doesn't mean her son is ungrateful; it means Olivia succeeded. When the first generation in a family graduates from college, they don't just lift up themselves, they lift up their descendants. The children of college graduates are far more likely to go to college too. If they go to college right after high school — as Mason does — they have a much better chance of graduating than if they wait, as Olivia did. And so they can worry a little less about whether they'll get a degree, and a little more about whether college will give their life meaning.

This is an old, old progression. "My sons ought to study mathematics and philosophy, geography, natural history… commerce, and agriculture," John Adams wrote in 1780, "in order to give their children a right to study painting, poetry, music." Olivia studied psychology; Mason is studying photography. The longer your family has been going to college, the less practical you can afford to be.

What education policy debates can learn from Boyhood

The social mobility narrative and the coming-of-age narrative get lumped together for at least one good reason: no matter who you are, college feels expensive.

When President Obama talks about college affordability, it resonates with a low-income student trying to juggle community college with work. But it also rings true to a family with a six-figure income trying to afford $60,000 per year for a private university.

This muddle can be politically advantageous. Benefits that go mostly to the poor, like Pell Grants, can be framed as "college affordability," which appeals to almost everyone. But it makes it harder to acknowledge that not all college affordability problems are equal. When the Obama administration tried to cut tax benefits on college savings plans in order to expand a tax credit for families making less than $160,000 per year, they ran into a brick wall of opposition from wealthier constituents who feel college is expensive for them, too.

Those challenges are not the same. Politicians and public policy should recognize that. Paying for a private college that costs three times as much as in-state tuition at a public university is much different from trying to figure out how to get $500 for a semester of community college.

A poignant scene near the end of Boyhood shows this perfectly. Olivia, her daughter Samantha, and her son Mason are at a restaurant; Samantha has a hangover and is complaining that she won't be able to do laundry at her mom's house anymore. In other words, she's being a pretty typical college student.

Then the restaurant's manager walks up to their table. He's a familiar face: the septic system repairman whom Olivia had once urged to go back to school, a few years and several scenes earlier. "You changed my life," he tells her. "I signed up for English classes. A year later I went to community college… Now I'm working on my bachelor's degree at Texas State."

Everyone in that scene — the manager, Samantha, Mason, and Olivia — has been, is, or will be a college student. All of them could be described as typical. But they have very different answers to the biggest question in higher education: What is college for? The answer, Boyhood suggests, is as much about where you're coming from as about where you want to go.