15 things you didn't know about '13 Going on 30'

Garner also said she was a big fan of working with Ruffalo in the film.

"Mark [Ruffalo] is an out-of-control, unbelievably amazing actor. Five years ago if you had said, 'List three or four actors that you would love to work with,' he would be at the top of my list," she said in the behind-the-scenes feature.

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"Our first meeting was a rehearsal, it was read-through," Ruffalo said in the documentary, adding that there were a bunch of other producers and other people in the room, too.

In the documentary, Susie Desanto, the film's costume designer, said the clothes each character wears is representative of their growth.

Jenna Rink's closet, for example, has a lot of pinks and soft fabrics that a 13-year-old Jenna would have picked out. Lucy's wardrobe goes the opposite way and it starts to incorporate red and black pieces.

Lucy's dark clothing reflects her cutthroat tendencies and Jenna's reflects her return to who she used to be.

Desanto explained, "Jennifer's character has a huge character arc and how she changes and realizes who she is and the costumes have to tell that story."

The cast and crew filmed "13 Going on 30" on location in New York City, and they got shots in tons of places, from inside Central Park to under the Brooklyn Bridge.

"It was hot and sometimes beautiful and crowded," Garner said in the documentary. "Sometimes you'd have hundreds of tourists watching."

Before the younger versions of Jenna, Matty, and Lucy were cast, the older actors were going to portray younger versions of themselves.

According to Ruffalo in that same documentary, this idea "was talked about for some time" but the crew didn't think it would work out very well.

In the documentary, Greer said she was encouraged to say or do anything while filming "13 Going on 30."

"Judy Greer, without a doubt, is a comic genius. She knows how to take something that looks like nothing and spin it," Garner said. "Talk about improvising — she always can make a line that seems funny 10 times funnier."

According to the documentary, the first time Greer's mom met Alexandra Kyle — who plays young Lucy "Tom-Tom" Wyman in the film — she was blown away by how much the actress resembled her daughter.

Kyle said Judy's mother told her, "It's like seeing my daughter again."

In the documentary, Greer said she doesn't see the similarities between Kyle and her teenaged self, adding that she "looked like a little boy" when she was that age, and Kyle looked "gorgeous."

In a deleted scene from the movie, Matty urges Jenna to see a doctor get to the bottom of how she's feeling.

During the appointment, the doctor says she can't find anything wrong with Jenna and compliments her tattoo. When the door closes, Jenna frantically searches her body to find her mysterious ink.

Garner, Ruffalo, Greer, Serkis, and Larson have all had roles in Marvel-based movies.

Garner played Elektra in both 2003's "Daredevil" and 2005's "Elektra." Ruffalo played the Incredible Hulk in multiple "Avengers" films, and Larson starred as Captain Marvel in 2019.

Greer played Maggie Lang in 2015's "Ant-Man" and 2018's "Ant-Man And The Wasp."

Serkis, who played Jenna's boss in the movie, appeared as Ulysses Klaue in 2015's "Avengers: Age Of Ultron," as well as 2018's "Black Panther."

The now-iconic scene in the film where Jenna and Matty spontaneously nail Michael Jackson's "Thriller" dance almost didn't happen.

In the documentary, Garner said "nothing was more fun" than watching Ruffalo try to learn the "Thriller" dance. But Ruffalo doesn't exactly agree.

In a 2004 interview with Black Film, Ruffalo said, "The dancing was horrible. I almost didn't want to do this movie. I literally read it and I'm like 'I can't do this movie. I can't get up and do those scenes.'"

"I'm like 'white boy don't dance," he told the publication. "When [Jennifer Garner] dragged me out (onto the dance floor) she was literally dragging me out and I had hours of rehearsal with a dance coach who taught me how to do all the moves and stuff and still, when we got into actually shooting it and there were 300 extras around, I did not want to do that scene."

The movie's popular clique the Six Chicks featured two stars you might recognize today —Ashley Benson of "Pretty Little Liars" fame and Academy Award-winner Brie Larson.

Although Garner and Greer, who played Lucy Wyman, are frenemies in the film, the two are pals in real life.

"I just really love her so much, and she is such a special person ... ," Greer said about Garner in a 2018 interview with The Social. "There's not a lot of people in the world that deserve everything that they've gotten, and all the success, and she is one of them. I'm really happy for her."

After connecting with Garner on "13 Going on 30," Allen later went on to appear in "Ghosts of Girlfriends Past" (2009) with the actress.

Once again, she played a teenage version of Garner's character.

Christa B. Allen didn't have any acting experience before this movie, but, in the documentary, Garner said Allen really resembled her teenage self, which is one of the reasons she was cast.

According to the film's behind-the-scenes documentary "Making of a Teen Dream," Garner was directly asked to be in this movie after she won a Golden Globe for her role on the show "Alias" in 2002.

Garner said she'd never been offered anything directly before, and it was her "Alias" castmates who encouraged her to take the role of Jenna Rink.