box office dumb and dumber toPoor Lloyd and Harry. The perpetual underachievers of the "Dumb and Dumber" movies have been underestimated by everyone.

Certainly, few pundits expected much from "Dumb and Dumber To," the poorly reviewed sequel to a 20-year-old movie, starring a Jim Carrey whose box office strength has dwindled over the last decade. Besides, last week's champ, "Big Hero 6," seemed unstoppable and poised for a repeat victory, with about $35 million in likely earnings. "Dumber," by contrast, wasn't expected to top $29 million.

Nonetheless, "Dumber" confounded the sages and came out on top, with an estimated $38.1 million. How did it defy conventional wisdom for a come-from-behind victory?

Here are some of the ways:

Nostalgia isn't just for old folks. Sure, it's been 20 years since the 1994 original, but it's been in near-constant rotation on cable ever since. A whole generation has grown up watching the silly antics of Carrey and Jeff Daniels as the doofus duo. Second installments that follow the originals by more than a decade usually don't do well, but the initial film has dated reasonably well and has hardly been forgotten. It's no wonder that "Dumb and Dumber To" drew a mostly older audience, but still, some 43 percent of the audience was under 25, too young to have seen the 1994 movie in theaters.

Critics? What critics? OK, the movie got terrible reviews, even from critics who liked the original film. But if ever there was a franchise that was immune to the thoughtful reasoning of critics, it's this one.

Anticipation. Despite poor advance buzz, pre-sales were strong, according to Fandango. (By contrast, no one was going to buy advance tickets to "Big Hero 6" in its second week.) True, once the film opened, it earned just so-so word-of-mouth from moviegoers (measured by a B- grade at CinemaScore), but by then, it was too late.

Jim Carrey. He may not have had a sizable hit in 11 years (since "Bruce Almighty"), but in the right part, he's still a must-see. For many viewers, Lloyd Christmas is that part. Besides, he almost never plays the same role twice; he hasn't sequelized one of his own hits since "Ace Ventura: When Nature Calls" in 1995. So Carrey fans were expecting a rare treat when he reprised the role of Lloyd.

Weak competition among the newbies. "Big Hero 6" actually performed as expected and earned another estimated $36.0 million. "Interstellar" also held up well, earning an estimated $29.2 million in its second weekend. Even "Gone Girl," which has been out seven weeks, remained strong, finishing fifth with an estimated $4.6 million.

But "Dumber To's" rivals among new releases proved weaker than expected. Musical drama "Beyond the Lights" underperformed in fourth place by debuting with an estimated $6.5 million, about two-thirds what experts predicted. Jon Stewart's drama "Rosewater" opened on 371 screens but grossed only an estimated $1.2 million, settling for 13th place. Kirk Cameron's "Saving Christmas" opened in 39 more venues than "Rosewater" but debuted two rungs lower, with an estimated $1.0 million. To the extent that "Dumber" outperformed expectations, it did so at the expense of these three other new releases.

The Power of Stupid. Even though it's awards-hopeful season, full of thoughtful dramas ("The Theory of Everything") or brain-twisters ("Interstellar"), there's always room for smart – er, stupid – counter-programming. Besides, audiences have come to appreciate deliberately idiotic comedies over the past two decades, making stars out of Adam Sandler, Will Ferrell, and Seth Rogen for playing overgrown man-children. A lot of that can be traced back to the Farrelly brothers successfully raising -- er, lowering -- the bar with the initial "Dumber" 20 years ago. No wonder the franchise continues to succeed; we live in the cinematic world that "Dumb and Dumber" built.

categories Movies, Box Office