In some movies you feel like you're a very small part of a huge machine. Whereas in the theater you can have a very small part but you can still feel the weight and the gravity of it. Given the nature of theater it's a more concentrated and quiet experience.
When my mom ran for the Senate my dad was there for her every step of the way. I can still hear her saying in her beautiful voice 'Why should women have any less say than men about the great decisions facing our nation?'