Watching Ben Stiller’s modern movie version of the 1939 James Thurber short story feels a little like cheating on your English homework, but is that such a bad thing? Then again, why do you still have English homework? Didn’t you finish school a long time ago? Wait, are you dreaming right now? And is this really the best you can do? Snap out of it. Stiller directs and stars as the titular submissive fantasizer, a “negative asset manager” for Life magazine who finds himself trotting the globe to track down a lost photograph for the final print issue. Gently encouraged by Kristen Wiig as his love-interest officemate, challenged by Adam Scott as his bullying new boss, and enlightened by Sean Penn (worth waiting for) as the rugged photographer of the elusive negative, Mitty eventually makes his dreams come true — even if the thing called Life might no longer need him thereafter. Of course Stiller takes many liberties with Thurber’s old chestnut, but there is a sense that its theme of yearning somehow really means something to him. It works better in the funny weird moments than in the over-soundtracked heartstring-tugs, but the latter aren’t all bad. Going beyond the gratuitous CGI stagings of elaborate fantasies, Stiller also graciously encourages you to get out of your head once in a while, and go visit Iceland or the Himalayas.