I Am Sam is the story of Sam Dawson, a man with the mental capacity of a 7 year old. Sam works at a Starbucks and is obsessed with The Beatles. After Sam has a child with a homeless woman, she abandons Sam with the girl who he names Lucy Diamond. Once Lucy reaches seven, she initially gets herself held back to avoid looking smarter than her father. The authorities take Lucy away and Sam gets high priced Rita Harrison to take his case pro bono to fight for his custody.