“I think the learning part of high school is over,” says restless senior Christine, self-nicknamed Lady Bird, in Greta Gerwig’s directorial debut, Lady Bird, which premiered here at the Telluride Film Festival on Friday. The joke is that all Lady Bird is doing is learning—just maybe not in an academic sense. Gerwig mined her own Sacramento adolescence to write the film, which has the sharpness and specificity of lived experience. It’s a winsome bit of autobiography that rings with bittersweet truth, though some navel-gazing solipsism does creep in.

What Gerwig does best is acutely capture the heady blur of the last year of high school, when old things gradually matter less and less as new opportunity and excitement tantalizingly tease on the horizon. Lady Bird dreams of leaving behind flat, sunshiny Sacramento and moving to New York for school—or Connecticut or New Hampshire, where, she imagines, people spend their time writing in the woods. Many a young creative type has felt a similar yearning, including, I’m sure, plenty of people in the audience at Telluride. Which made for an effective crowd-pleaser on Friday night, even if the film is too scattered and slight to make a significant, lasting impact.

Lady Bird is helped tremendously by Gerwig’s finely curated cast. Saoirse Ronan, always a compelling mix of soulful and thoughtful, plays Lady Bird’s jumble of emotions with natural, salient insight. She’s needy and curious, bored and hungry, funny and sometimes more than a little mean. You can see the potential blooming in her, and the adventure of the film, if there is an adventure, is watching that inner light wrestle its way to the surface. Ronan, a good five years older than high-school age, never condescends to the character by playing up the cluelessness of her youth. Instead she’s sympathetic and smart, piquantly, appealingly giving voice to Gerwig’s admirably un-precocious teen dialogue.

Lady Bird spars with her rigid but loving mother, Marion, played by the great genius Laurie Metcalf. These scenes are highlights of the film, somehow both endearing and bruising, a prickly and complicated mother-daughter dynamic that will prove achingly familiar to many. Under Gerwig’s calm, artful guidance, Ronan and Metcalf never tip into hyperbole or canned melodrama. Their relationship remains firmly in the bounds of actual humanity, giving the film a refreshing and lived-in vibe that helps drown out some of its recurring problems.

As is often a peril with this kind of thinly veiled autobiography, Lady Bird can, at times, be a bit too precious about its author’s experiences. The film’s specificity is mostly an asset, but one does get the feeling while watching it that certain details—ones that no doubt mean something important to Gerwig—are extraneous and distracting. The film could use a bit more shaping. As is, it’s a pleasant series of loosely connected events capped off with a coming-of-age lesson.

More broadly, it’s never made quite clear enough what is so special about Lady Bird. The film itself is proof that her real-life counterpoint has done quite well for herself. If we were to watch Lady Bird in a vacuum, though, with no idea of who Gerwig is, I wonder if it all might seem a tad listless and arbitrary. Sure, Lady Bird is fun to spend time with. But the larger drama of the character’s mild arc—the film is ultimately a story of learning to appreciate where and whom you come from, while still seeking out something new—doesn’t have all that much heft without its meta context.