There's no explosions in this film. There's no sex, or car chases. No one is on the run for a crime he didn't commit, and there is no secret society of mischievous frat boys. No actor was cast because of their looks alone and the only real action going on is when someone gets hit by a car. But we don't get to see that. We just see what happens afterward.
Instead, this film is about people. Normal everyday people who wear normal everyday clothes and do their normal everyday jobs. And they have normal everyday conversations. 13 of 'em.
This is a thinking person's movie.