Lady Bird is a perfect coming-of-age comedy for anyone who’s ever had teenage wanderlust, fought with their parents, fostered a love-hate tension with their hometown or popped Communion wafers in secret.

Writer Greta Gerwig's witty and endearing solo directorial debut (***½ out of four; rated R; in theaters Friday in Los Angeles and New York, expanding through November) navigates the absurdities and struggles of the transition into adulthood while striking an excellent balance between enjoyable quirk and touching emotion. An ode to being weird and embracing one’s true self, Lady Bird is powered by spectacular performances from Saoirse Ronan and Laurie Metcalf, both instant Oscar contenders as a daughter and mother whose relationship is fraught with resentment but never lacks love.

Christine McPherson (Ronan) insists that everyone call her Lady Bird, a nod to the fact she can’t fly out of her hometown of Sacramento fast enough. Seemingly stuck in “the Midwest of California,” Lady Bird hatches grand plans to attend college in more cultured New York City, and her senior year of Catholic school is filled with young romance, drama club, friendships broken and fixed, and lots of family strife.

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Gerwig expertly paces Lady Bird’s journey and her script sparkles with sarcasm (“The only thing exciting about 2002 is it’s a palindrome”) as well as clever dialogue. When best friend Julie (Beanie Feldstein) asks Lady Bird if she’s worried about Big Apple terrorism, she responds, “Don’t be Republican.”

Ronan delivers such lines in a faux caustic manner — she never quite goes full rebel — yet with a certain vulnerability that hints that even she doesn’t totally believe she’s that enigmatic. As cool as she is, Lady Bird can only muster a “Come here often?” when faced with a cute boy from school at the grocery store, and that push-and-pull between extreme self-confidence and frustrating insecurity is one of the movie’s most relatable aspects.

Lady Bird has a knack for exaggerating familiar moments to mine extra levity, and its characters' oddball school life is reminiscent of Napoleon Dynamite. (Example: Hilarity ensues when the school play is taken over by the JV football coach.) Just as often, though, Gerwig offers poignant moments as well, notably between Lady Bird and her parents — with whom she has polar opposite relationships.

Her dad, Larry (Tracy Letts), is a quiet sort, dealing with changes at his work and trying to keep the peace at home, and he’s often caught in the middle of the contentious blowups between Lady Bird and her mother, Marion. She constantly questions Lady Bird’s life choices and comes down hard when her daughter acts like a teenager, especially when it comes to her kid’s appearance and actions.

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Metcalf never goes full Mommie Dearest, however — Lady Bird and her mom are at loggerheads frequently, yet there’s such a depth to the opinionated matriarch as she becomes the family's primary breadwinner that you’re on her side as well. The actress keeps her stone-faced and passive aggressive most of the film, and when the emotional dam breaks, it’s cathartic for Metcalf as well as the audience.

Lady Bird is a fantastic twist of familiar teen-movie tropes but doesn't forget how hard it is to be a parent either.