I first saw this trailer while going to see "We're the Millers," and I've watched it on YouTube about a thousand times since.
Based on a 1939 short story which was later adapted into a 1947 film, it follows the daydreams of the titular character, Walter Mitty. The original short story was only six pages long. It was merely an hour or so in the life of Walter Mitty as he accompanied his wife on errands while daydreaming about much more exciting things than new shoes.
Haven't we all been there? Bored by the mundane details of everyday life, and filling that boredom with fantasies of greatness? Needless to say, my fantasies as of late are mainly centered around Boston.