In "Greenberg," Roger Greenberg (Ben Stiller) has returned from New York to his native Los Angeles after suffering a nervous breakdown. Roger is trying to "do nothing" for a while, and so he's house-sitting for his brother while the latter vacations with his family in Vietnam.
Roger, a carpenter, spends his time writing letters of grievance. He takes care of his brother's dog, who suddenly becomes ill. He listens to the complaints of old friends who blame him for breaking up a rock band supposedly on the brink of success. He spends time with a former girlfriend, Beth (Jennifer Jason Leigh), and friend, Ivan (Rhys Ifans). Beth and Ivan, though they've had difficulties in their respective marriages, are, unlike Roger, trying to be responsible adults. Roger, 41, is involved–sort of–with his brother's personal assistant, Florence Marr (Greta Gerwig), 25, who also sings at a bar.
The disconnected dialogue among various characters and Roger's drifting give the film a realistic, "slice of life" feel. That would be fine, except for the fact that this main character doesn't evoke much sympathy or, ultimately, interest. He's difficult and unpredictable with friends and especially with the passive Florence, and he rationalizes his own behavior with psychobabble. Florence is also something of a lost soul, but why she continues to bother with this self-indulgent, aimless individual almost twice her age is a mystery.
Roger tells Florence that he shouldn't be completely defined by his stay in a mental hospital, and, by that standard, we shouldn't excuse his bad behavior by constantly reminding ourselves of his recent emotional state. As the film concludes and Roger has to make a decision about his relationship with Florence, one only wants to advise her to ditch this guy. Viewers new to the films of Noah Baumbach should instead take in the humorous and poignant "The Squid and the Whale" (2005).