A fiercely inquisitive performance from Annette Bening buoys this otherwise pedestrian indie drama by writer-director Mike Mills (Thumbsucker, Beginners), who based Bening’s character on his own mother. The film takes place in Santa Barbara in 1979, when the eccentric single mother is 55 and her late-arriving son (Lucas Jade Zumann) is 15; fretting over his lack of a male role model, she enlists one of their boarders, a young photographer with cervical cancer (Greta Gerwig), to educate him about women, though a bitter lesson comes in the form of the classmate he adores (Elle Fanning), who climbs through his bedroom window every night looking for friendship but gives her body to any guy but him. Mills digs deep into the era, with the mother struggling to make sense of punk rock; the film has the feel of a memoir, in both its effortless authenticity and its limited significance. With Billy Crudup.