Fidgety, fast-talking indie roles in The Squid and the Whale and Zombieland built the persona. David Fincher weaponized it. As Mark Zuckerberg in The Social Network, he turned social awkwardness into something genuinely threatening, playing a guy who wasn't likable so much as he was terrifying to be in a room with. The film grossed $224 million on a $40 million budget, and the Academy nominated him for Best Actor. He lost to Colin Firth. The performance stuck around anyway.
A Real Pain was the kind of career move that reframes everything. He wrote it, directed it, and starred in it: a road trip with his cousin (Kieran Culkin) through Poland to pay tribute to their late grandmother. It won him a BAFTA for Best Original Screenplay and an Oscar nomination. He received Polish citizenship in March 2025, granted by the President of Poland. He's also developing an A24 musical comedy with Julianne Moore and Halle Bailey, writing original music and lyrics. The indie auteur lane suits him better than Lex Luthor ever did.
Acting started as a prescription. He's said the ritualistic structure of rehearsal and performance gave his OCD and anxiety disorder somewhere to go, after years of describing himself as 'a miserable kid.' He's also said he deliberately channeled those same tics into Zuckerberg's social stiffness. At 16, he wrote a screenplay about Woody Allen that earned him two cease-and-desist letters. He later starred in Allen films anyway.