Why would a couple of over-40 dudes, director David Fincher and screenwriter Aaron Sorkin, make a movie about something they don’t even use? The generational divide that is Facebook hardly seems suited to film. Oldsters who abhor Facebook don’t want to watch youngsters coding, and youngsters would presumably rather be home using Facebook than see a movie about its founder, Mark Zuckerberg (Jesse Eisenberg). Yet this Golden Globe winner and Oscar favorite succeeds by placing its arrogant, touchy, passive-aggressive dork hero at the center of a buzzing hive of spurned love, betrayal, and hurt feelings. Based on the book The Accidental Billionaires by Ben Mezrich, the movie weaves back and forth among legal depositions after Facebook’s success and the early Harvard days where Zuckerberg—depending on whose account you believe—stole ideas from several parties to create that nascent website. Sorkin specializes in dialogue among very smart, articulate, and flawed people. No one’s an outright villain, because everyone contributes something valuable to Zuckerberg’s rolling ball of snow. It just keeps getting larger with every idea he overhears, borrows, or originates. His genius is to give Facebook “exclusivity,” like those private clubs at Harvard he longed to join. (He’s Gatsby without the looks or charm.) Fincher and Sorkin never consider whether Facebook is a good thing or not. That it today has a market cap of $25 billion and 500 million users is unquestionably a good thing. But the cost for this lonely mogul, in Fincher and Sorkin’s estimation, is to be a silicon Citizen Kane who can never reboot his life.