Plot
In 1979, 15-year-old Jamie Fields lives in Santa Barbara with his 55-year-old single mother, Dorothea, and their two tenants: Abbie Porter, a 24-year-old photographer being treated for cervical cancer, and William, a carpenter and mechanic. Jamie's best friend is 17-year-old Julie Hamlin.
Concerned she is having trouble connecting with her son, Dorothea asks Abbie and Julie to help raise him, but Jamie responds to this by going to a rock concert in Los Angeles with some friends. When he returns, Julie tells him she had unprotected sex. Jamie accompanies Abbie to a doctor's appointment, where she learns she is cancer-free but will likely be unable to have children, and he reads a magazine article about home pregnancy tests. He buys one for Julie and helps her take it. It comes back negative. To thank Jamie for his support, Abbie makes him a mixtape, and she begins to confide in him, telling him she moved back home from New York after her cancer diagnosis, but her mother could not handle that the cancer was caused by her use of DES, a fertility drug, while Abbie was in utero, so Abbie moved in with Dorothea.
One day, after seeing Julie sneak out Jamie's window, Dorothea talks with her, and they discuss why Dorothea has had no real relationships since Jamie's father left years earlier. Dorothea asks Abbie to show her "the modern world", so they go to a punk club, where William kisses Dorothea. Aware that he has a sexual relationship with Abbie, Dorothea does not return his advance. Abbie gets in a fight and William tells her he no longer wants to sleep with her. Abbie goes to talk to Jamie and, finding him in bed with Julie, says Julie is disempowering Jamie and advises them both to leave Santa Barbara.
Jamie asks Abbie to take him to the club, and he gets drunk and kisses a woman. Meanwhile, Dorothea teaches William how to pursue a serious relationship, as opposed to casual sex. When Abbie tells Dorothea about Jamie's night, Dorothea is not upset, though she is wistful that, as his mother, she can never see what Jamie is like out in the world.
Abbie lends Jamie some books about feminism, and he finds them interesting, but Dorothea thinks they are too much for him and scolds Abbie. At a dinner party, Abbie says she is tired because she is menstruating, and, frustrated by the discomfort the word causes, she makes everyone at the table say "menstruation". Julie then describes her first period and first sexual encounter, and Dorothea ends the gathering.
Jamie tells Julie he no longer wants her to spend the night if she just wants to talk. Hurt, she suggests they take a road trip up the coast. At a hotel, Jamie says he loves Julie, but she says she feels too close to him to have sex. They argue, and Julie accuses Jamie of being like "other guys". Jamie storms off. Julie calls Dorothea, but by the time she, Abbie, and William arrive, Jamie has returned. Dorothea tells Jamie that she asked Abbie and Julie for help because she wants Jamie to be happier than she is, and he says he thought they were doing fine already. The two make up and return to Santa Barbara on their own, and Dorothea talks openly about her feelings and dreams for the first time.
An epilogue reveals that Julie goes on the pill, attends NYU, loses touch with Jamie and Dorothea, falls in love, moves to Paris, and chooses not to have children. Abbie stays in Santa Barbara, gets married, sets up a photography studio in her garage, marries, and has two sons. William lives with Dorothea for another year, moves to Sedona, opens a pottery store, and gets married and divorced before settling down with another woman. Dorothea meets a man in 1983 and stays with him until her death from metastatic lung cancer in 1999. Years after her death, Jamie marries and has a son to whom he unsuccessfully tries to describe Dorothea.
