Rambo, a mathematics professor at MIT, announced a difficult math problem at the meeting, but it was solved by the young cleaner Will (Matt Damon). But Will was a problem teenager, hanging around with his good friend Chuck (Ben Averett) and others all day, fighting and making trouble. When Rambo found this genius, he was sentenced to detention by the court for fighting and assaulting the police. Rambo asked the judge for bail, which saved him from jail. In order to let Will find his life goal and not waste his mathematical talent, Rambo invited many psychology experts to counsel Will, but Will was very resistant and the experts were helpless. With no other options, Rambo turned to his college friend, psychology professor Sean (Robin Williams), hoping to help Will open his heart. After Rambo and Sean's unremitting efforts, Will gradually opened his heart, and his friend Chuck's words made him suddenly enlightened.