Patton Oswalt talks about his role as an eHarmony consultant in 'The Secret Life of Walter Mitty'

The Secret Life of Walter Mitty features Patton Oswalt as an eHarmony consultant, helping Ben Stiller's character make his profile more interesting in an attempt to portray his life as less dull and empty.

Stiller's character, a man who cannot escape daydreaming about what his life could be like otherwise, definitely can use the help from Oswalt's character in the film. It isn't clear if consultants like that for dating sites really exist.

"I can't speak from experience - I don't know if they have reps like that," Oswalt laughs, talking to Rolling Stone. "I've never been on a dating site. I've always done face-to-face."

Oswalt's character is the one who is trying to bring Mitty back to reality and break him away from such a fantasy driven existence. Mitty, an unfulfilled film-processor, imagines what it would be like if his life was made up of action sequences, if he was a hero.

"He keeps the irony going, no matter how far Walter actually travels," Oswalt explained. "He's the one guy who keeps calling him - the guy who's trying to connect him with the rest of the world."

Most of Oswalt's dialogue in the film is just voice work because he's calling to check in and help Mitty, but that didn't mean he was in a booth somewhere else, not actually interacting with Stiller or the rest of the cast and crew.

"Ben always wanted me on set so that we could riff scenes, so I was very rarely ever just on the phone with him," Oswalt said. "I even went to Iceland to work off-screen with him. So as much as it was a voice-over performance, it was very active in terms of being present."

Not only was it important to be present literally, but the theme of the entire film is what it means to be mentally present with your current reality, and Stiller addressed this idea in a unique and impactful way. "Ben's made an epic level comedy, and it's amazing how as big as the film gets, it still feels so intimate," he said. "I've never seen that juxtaposition done so effortlessly in a film before."

The Secret Life of Walter Mitty comes out Christmas Day.