Although she doesn't admit it, Mavis (played by Charlize Theron) is a classic older single woman. She lives alone, has no friends, eats junk food, and writes terrible novels, and more sadly, her novels don't sell well. One day, she receives an email from her ex-boyfriend Buddy (played by Patrick Wilson) who has become a father, and mistakenly believes it is a sign of his interest in her. Excited, Mavis decides to change her appearance and return to the town of Mercury where she used to live as a student, to save her ex-boyfriend who is trapped in the chaos of marriage. In Mercury, she encounters Matt (played by Patton Oswalt), the overweight boy she used to mock. Matt advises her to give up on the idea of breaking up Buddy's marriage because Buddy is actually very happy with his life, and his wife is a charming housewife. Mavis, of course, doesn't believe him, but reality gives her a harsh slap in the face. After making a fool of herself in front of her old classmates, Mavis suddenly realizes that Buddy's happy life fills her with jealousy, but isn't her own life the 'best life' in others' eyes as well? Overnight, Mavis transforms from a 'teenager' into a true 'adult'.
