For anyone who has read and enjoyed James Thurber’s short story “The Secret Life of Walter Mitty” (and, if not, I highly recommend you set aside the ten minutes required to do so), Ben Stiller’s film version may come as a bit of a shock. Not because Stiller took a 15-paragraph story and turned it into a 2-hour film… but because somewhere along the way he forgot about the story’s whimsy and fun and decided instead to turn it into his own y-chromosome version of Eat, Pray, Love.

The tale of a man who daydreams with reckless abandon, “Mitty” remains one of the most beloved short stories of all time (almost 75 years since it was first published) because of both its pithiness and invention. The beleaguered Mitty dreams of being an Air Force pilot, a life-saving surgeon, and a devil-may-care murder defendant, all in the space of a few thousand well-chosen words.

Stiller (who also produced the film) stars as the titular dreamer—here a darkroom drone during the waning days of Life magazine’s print edition. He’s smitten with co-worker Cheryl Melhoff (Kristin Wiig), but all he can do about it is daydream of impressing her as a rugged ice climber or as the hero who saves her dog from an exploding building.

When his personal hero, photographer Sean O’Connell (Sean Penn), sends Walter the cover photo for the magazine’s last issue, Walter promptly loses it (…though you’ll figure out, long before Walter does, where the missing photo is). Walter sees this as an opportunity to get his head out of the clouds and embark on a real-life adventure to find the globe-trotting O’Connell and the missing photo.

Before you can say Nuuk, Walter is jumping out of a helicopter off the coast of Greenland, fighting off sharks, and then he’s off to try his hand at extreme longboarding into an erupting volcano. All this from a guy who, only a few days earlier, barely had the guts to “wink” at Cheryl’s eHarmony profile.

There’s no doubt that Stiller saw Mitty as the perfect opportunity to travel to nifty places and try studly things, but somewhere along the way, he let it get the best of him (and the movie). What starts as a clever and witty comedy unfortunately morphs into one man’s personal quest for testosterone and (to a lesser extent) an awakening. Part travelogue, part “find-yourself” drama, Mitty ends up doing neither successfully, and both have nothing whatsoever to do with the source material. Plus, the obscene product placement for everything from Cinnabon to Papa John’s doesn’t help matters.

Stiller, in all fairness, does deserve credit for some rather inspired direction, at least at the outset. His Wes Anderson-esque style is a revelation of sorts (this is the same guy who directed Zoolander?), but that inventiveness is quickly overtaken by his inner David Lean (no offense, Mr. Lean), and Mitty becomes more of a sprawling drama bathed in the gentle glow of a Nordic sunset.

It’s screenwriter Steve Conrad, also responsible for 2006’s ultra-maudlin The Pursuit of Happyness, who may be most to blame here, though. Had he allowed the spirit of the original story to survive for more than just the first half-hour, The Secret Life of Walter Mitty may well have been a success—a charming and fun film, perfect for the holiday season. Alas, it winds up as a bloated and overly sappy mess, with glimpses of promise but not much more.

Now, seriously, go read the short story.

2/5 stars