Every decade or so, a film comes along that’s emblematic of the zeitgeist of a generation, a coming-of-age movie, a film where the audience in the theater makes discoveries along with the characters on the screen as they awaken to self-discovery, the verities of life, and some often unforgiving truths.

“Lady Bird” is one such film.

“Rebel Without a Cause” (1955), “The Graduate” (1967), “American Graffiti” (1973), “The Breakfast Club” (1985), “Clueless” (1995) and “Juno” (2007) are among the seminal films that came to define the hopes, dreams and disappointments of a particular generation once upon a time in the life of teenagers.

During the best scenes in these films, teenage angst is handled with humor, with seriousness and with care. Often, such films reference pop iconography of their decade, or reference a previous era, to understand contemporary dilemmas and dichotomy.

“Lady Bird” is a stunning solo feature-film directorial debut for Greta Gerwig, who also wrote the screenplay. Gerwig codirected and co-wrote with Joe Swanberg the feature film, “Nights and Weekends” (2008), wrote the screenplays for the feature films, “Frances Ha” (2012) and “Mistress America” (2015), and was a co-writer of screenplays for the feature films, “Northern Comfort” (2010) and “Hannah Takes the Stairs” (2007). Gerwig stars in each of these films.

Gerwig doesn’t star or even appear in “Lady Bird,” but her presence is felt from behind the camera in every frame. While there are vestiges of her mumblecore film roots (“Baghdad,” 2008, and “Hannah Takes the Stairs”) with “Lady Bird,” Gerwig shows herself to be an accomplished director in the style of the great cinematic auteurs. She knows where to place the camera, she knows how to get sensitive and not sentimental performances, she has a clear sense of pacing, and an understanding of watching films, with a director’s eye. Look for several Oscar nominations for “Lady Bird,” including screenplay and director for Gerwig.

Gerwig chose her hometown, Sacramento, California, as the 2002-03 setting for the title character, Lady Bird (Saoirse Ronan), a 17-year-old female parochial school student on the cusp of adulthood, college (she wants to attend Columbia University, New York City) and creative differences, to put it mildly, with her mother (Laurie Metcalf), and seemingly on the outs with most of her fellow students.

Teen traumas: high school theater (Stephen Sondheim’s “Merrily We Roll Along,” a nice touch that gives the film some of its manifest puckish energy, and William Shakespeare’s “The Tempest,” which underscores the film’s third act more somber concerns); proms (a cute corny country and western theme and a prom as serious as going solo); the dysfunctionalism that is unfortunately all too common between mother and daughter; the heartfelt emotional minefield of first love and lasting realities, the social status, economic and school class competition, rivalry and petty jealous that are all part of leaving behind pimply puberty, and exploring belief, with faith depicted as a seed planted, growing and deepening.

Gerwig weaves the concomitant emotions, actions and reactions with an awareness of one who’s been there.

Ronan (Oscar nominee, Actress, “Brooklyn,” 2015, and Supporting Actress, “Atonement,” 2007) plays Christine “Lady Bird” McPherson. Ronan, 23, has no problem playing a 17-year-old. She’s completely believable in the role. And while her character might be labeled a loser by her peers, she’s a winner for the moviegoer. Ronan gives a vulnerable, all-in, transcendent performance. Look for an Oscar actress nomination for Ronan.

Metcalf (“The Big Bang Theory,” 2007-17; voice, “Toy Story” movies; three-time Primetime Emmy recipient, TV’s “Roseanne,” 1988-97) is at the moral center of the film as Marion McPherson, the mother of Lady Bird, a truly thankless task. This is a battle of the sexes, the same sexes, for superiority, feminine territory and individuality. Metcalf illuminates the role with an on-point, rueful and marvelous turn as a long-suffering mother who’s keeping the family intact. Look for an Oscar supporting actress nomination for Metcalf.

Lucas Hedges (Oscar nominee, supporting actor, “Manchester by the Sea,” 2016; “Moonrise Kingdom,” 2012) is heartbreaking and inspiring as Danny, Lady Bird’s first teen love.

Beanie Feldstein is notable as Julie, Lady Bird’s best friend. Odeya Rush plays the spoiled rich girl, Jenna, with relish and without making her hateful. Timothée Chalamet has a great presence as Kyle, a politically aware student. Tracy Letts is sympathetic as Larry McPherson, Lady Bird’s dad.

“Lady Bird” is nominated for four Independent Spirit Awards: Female Lead (Ronan) Supporting Female (Metcalf), Feature, and Screenplay (Gerwig). The National Board of Review singled out Gerwig as director and Metcalf as supporting actress for its 2017 film accolades.

“Lady Bird” is an exuberant paean to the joys and challenges of family and friends, of hometown and of life goals lost and found. It’s a charming looking-back and a leave-taking even as it drives confidently into the future. Don’t miss it.

“Lady Bird,”

MPAA rated R (Restricted Under 17 requires accompanying parent or adult guardian. Contains some adult material. Parents are urged to learn more about the film before taking their young children with them.) for language, sexual content, brief graphic nudity and teen partying; Genre: Run time: 1 hr., 34 min.; Distributed by A24.

Credit Readers Anonymous:

“Lady Bird” opens with the on-screen quote: “Anyone who talks about California hedonism has never spent a Christmas in Sacramento.” - Joan Didion

Box Office,

Dec. 1: “Coco” puffed to No. 1, two weeks in a row, with $26.1 million, $108.6 million, two weeks. “Justice League” stayed at No. 2, with $16.5 million, $197.3 million, three weeks. “Wonder” was again No. 3, with $12.5 million, $88 million, three weeks. “Thor: Ragnarok” continued at No. 4, with $9.6 million, $291.4 million, five weeks. “Daddy’s Home 2” was again No. 5, with $7.5 million, $82.8 million, four weeks. “Murder on the Orient Express” again steamed along at No. 6, with $6.7 million, $84.7 million, four weeks. “Lady Bird” flew up four perches to No. 7, with $4.5 million, $17 million, five weeks. “Three Billboards Outside Ebbing, Missouri” tracked up two spots to No. 8, with $4.5 million, $13.6 million, four weeks. “The Star” slipped two places to No. 9, with $4 million, $27.2 million, three weeks. “A Bad Moms Christmas” slid down two places, to No. 10, with $3.4 million, $64.8 million, five weeks.

Unreel,

Dec. 8:

“The Shape of Water,”

R: Guillermo del Toro directs Sally Hawkins, Octavia Spencer, Michael Shannon, and Doug Jones in the fantasy film set in the United States in 1962 during the Cold War. Two U.S. government laboratory workers discover a secret experiment.

“Just Getting Started,”

PG-13: Ron Shelton directs Glenne Headly, Morgan Freeman, Tommy Lee Jones, and Rene Russo in the action comedy. An ex-FBI agent and an ex-mob lawyer in the witness protection program put their differences aside to fight crime.

“I, Tonya,”

R: Craig Gillespie directs Margot Robbie, Sebastian Stan, Bojana Novakovic, and Allison Janney in the biography drama. Ice skater Tonya Harding’s U.S. Figure Skating Championships career is profiled.

Five popcorn boxes out of five popcorn boxes.