A new eye-popping trailer for "The Secret Life of Walter Mitty" delves deeper into the back story behind the fantasies of our titular hero, who longs for far-flung adventure while living a humdrum life in New York City.

Walter (Ben Stiller) would rather daydream about his cute coworker (Kristen Wiig) than actually talk to her, imagining he's a world explorer telling impressive tales to win her over. He hides behind an online dating profile he can't figure out how to operate, explaining to a perplexed customer service operator his lack of description about himself: "I haven't really been anywhere noteworthy or mentionable."

"Have you done anything noteworthy or mentionable?" the operator asks a silent Walter.

As we see in the trailer, things are about to change. Wiig's character tells him, "Life is about courage and going into the unknown." Looks like Walter's about to jump in headfirst.

"The Secret Life of Walter Mitty" opens Christmas Day.