Starring Saoirse Ronan. Rated 14A

Period pieces are often dipped in amber, ensuring that nostalgia can do much of the heavy lifting. The recent past is a harder sell, given its freshness in living memory, and Greta Gerwig pulls off an even more difficult trick: depicting her own millennial adolescence in the sun-bleached Sacramento Valley of the early aughties.

Although initially known for manic-pixie roles in ramshackle indie films from the mid-2000s, Gerwig cowrote and codirected one of her first efforts, Nights and Weekends, with mumblecore auteur Joe Swanberg. For the phenomenal Lady Bird, she makes the most of her solo flight behind the camera the old-fashioned way: with a supertight script and a uniformly first-rate cast. It’s led by Ireland’s Saoirse Ronan, sporting a pitch-perfect Cali accent and Raggedy Ann hair as Christine McPherson, struggling to carve out a new identity in her last year at a Catholic school in a bland suburb.

Currently, she’s given herself the name Lady Bird, somewhat randomly picked and not even vaguely embraced by friends, teachers, or family members. The least sympathetic appears to be her mother, Marion (a superb Laurie Metcalfe), who clearly loves her daughter but is ready to go ballistic at the smallest challenge. Christine gets judgment-free support from her soft-spoken dad (Tracy Letts) and none whatsoever from her adoptive older brother (Jordan Rodrigues).

Our budding Bird, whose clothing style resembles no one’s around her, chafes at the restrictions of Immaculate Heart High School. And yet the good-natured head nun (’70s great Lois Smith) keeps failing to take her rebellious bait. Life changes slightly when she joins the drama club, the better to be around a new crush called Danny (Manchester by the Sea’s Lucas Hedges). This slight rise in social status further compels LB to trade her chubby long-time bestie (Beanie Feldstein) for the school’s most popular girl (Goosebumps’ Odeya Rush). Naturally, such dizzying heights also encourage a precipitous fall.

This may sound like fairly familiar teen territory, but Gerwig—who never appears on the screen but somehow never leaves it either—has such a sure hand at combining the weirdly personal with the universality of adolescence. No AMBER Alert is needed for the soundtrack, which skips obvious place-setters to favour oddball punk and twisted pop. That goes perfectly with someone who desperately wants to fit in but will always stand somehow apart—like this movie, which is better than almost anything else out there.