On this day in 2013, Disney Pixar’s ‘Monsters University’ was released in theaters. The film is Pixar’s only prequel to date and tells the story of how Sulley and Mike Wazowski became best friends in college. To understand university life, the filmmakers observed students and faculty at Harvard, Stanford, Cornell, and MIT. ‘Monsters University’ was the first Pixar film to use “global illumination,” an innovative new lighting system that mimics light in the real world.