Christine McPherson (Saoirse Ronan) is someone cursed with that familiar, often painful, gift of youth—absolute certainty. She feels everything strongly, expresses her opinions loudly, and both wounds and charms the people around her without meaning to. On the brink of adulthood, she’s resolute enough about her desire to go to college on the East Coast (far from her home of Sacramento) that she tosses herself out of a moving car when her mother Marion (Laurie Metcalf) tries to dismiss her...