The idea of anonymous letters came from a real experience; during his senior year in high school, Chbosky wrote an anonymous letter to Stewart Stern about how "Rebel Without a Cause" had influenced him. A year and a half later, Stern found Chbosky and became his mentor. By using a series of letters from Charlie to an anonymous character, Chbosky found "the most intimate way" to talk directly to the reader. He thought the letters would help him keep the story cohesive, "to convey the highs and lows of being young—one day, you're on top of the world and you've had the greatest of times".