Every year families gather to re-watch Christmas favorites as old as Betty Grable pinups. We know every line from “Rudolph, the Red-Nosed Reindeer” (1964), “Miracle on 34th Street” (1947) “It’s a Wonderful Life (1946) and “A Charlie Brown Christmas” (1965).

“A Christmas Story” is the new kid on the block, a relative pup at 31 years of age.

Then along came “Elf.”

The 2003 comedy starring Will Ferrell as Buddy, Santa’s overgrown helper nestled itself next to those Christmas classics.

It’s what Hollywood has been trying to do for some time with little success. Consider the flop-sweat stories that once auditioned for the gig: “Christmas with the Kranks.” “Deck the Halls.” “Surviving Christmas.” “Jingle All the Way.”

Just try sitting through any of them once, let alone once a year.

Tinsel Town loves film franchises, but scoring a new holiday classic is pop culture’s Holy Grail. Comic actor Artie Lange once boasted on “The Howard Stern Show” he gets residual checks for his tiny role in “Elf” given how often it plays each season.

Lange’s good fortune is ours, too.

“Elf” is a yuletide delight, a near-perfect combination of modern sensibilities and old-fashioned sentiment. Here are seven reasons why “Elf” became a modern Christmas mainstay.

A Man-Child Is Born: Will Ferrell’s film resume teems with arrested development types, from “Step Brothers” to “Talladega Nights: The Ballad of Ricky Bobby.” There’s even something child-like about Ron Burgundy, our favorite “Anchorman.” “Elf” marked the first time he trotted out that man-child shtick on the big screen, and he nailed it right out of the gate.

Santa-Worthy Slapstick: Christmas classics age better than most movies. Slapstick is equally resistant to Father Time – consider the comic legacies of Charlie Chaplin and Buster Keaton. “Elf” combines those two elements with sparkling results. Ferrell gobbles cotton balls, wrestles a fake St. Nick, does a split on an escalator and gets pummeled by an “angry elf” (Peter Dinklage). And, best of all, never has a comedian’s height been put to such grand purpose than Ferrell’s lanky frame clad in yellow tights.

Shower Time with Buddy: Ferrell’s accidental bathroom duet with co-star Zooey Deschanel isn’t naughty but oh, so nice. The pair sing the courtship classic “Baby, It’s Cold Outside,” the first chapter in the couple’s unlikely romance. Deschanel, a recording artist away from the big screen, serves up a delicate take on the song. Ferrell’s tentative verses reveal Buddy’s lovable naivety.

An Elf Out of Water: Some comic staples never grow old. Consider the “fish out of water” template, used so brilliantly in “Crocodile Dundee.” In “Elf,” we watch Buddy giggling his way through a shoe shine, chewing gum left behind on a subway fence, spinning a revolving door like a top and otherwise behaving like he’s never stepped foot in a city like New York. He hasn’t, and his sense of discovery is magical.

James Caan Channels Charles Dickens: Veteran actor James Caan plays Buddy’ father, a publishing executive with little patience for holiday mischief. He’s Ebenezer Scrooge and Bob Cratchit rolled into one, with a pinch of the Grinch for good measure. When Buddy finally captures daddy’s heart it links back to Dickens’ yuletide awakening.

No Sequel, No Problem: “Elf” is 11 years old, and there’s not so much as a rumor about a sequel, reboot or re-imagining despite the film’s cult status. Ferrell has gone on record saying a sequel doesn’t interest him, a rare sign of artistic restraint in an industry starved for hits. No matter how good it might be to see Buddy and friends again, any new “Elf” project would diminish the original.

Tip of the Elf Hat to the Classics: Few knew back in 2003 “Elf” would one day join the likes of “A Christmas Story” and other yuletide staples. The movie wisely acknowledged the tall task before it all the same. Consider the animated sequences honoring “Rudolph,” with a stop-motion snowman standing in for Burl Ives. It’s one of several sly odes to previous Christmas fare. Someday, we may see a future holiday film name-check Buddy and friends.

Christian Toto is an award-winning journalist, film critic and fatherhood blogger. You can find more here.