Jennifer Garner and Mark Ruffalo cuddling on couch
EW | Paramount Pictures

Interesting Facts About Iconic Rom-Coms Fans Should Know

If you're a fan of rom-coms, there's a good chance that you've seen the same ones, again and again.

You've memorized the meet-cutes and could recite every last detail of the first kisses. But even some diehard fans still don't know everything.

Like, did you know that Mark Ruffalo hated that dancing scene in 13 Going on 30 or that Billy Crystal and Meg Ryan almost weren't in When Harry Met Sally?

For more shockers, here are 16 interesting facts.

1. Christa B. Allen was cast as a young Jenna in '13 Going on 30' because she looked so much like a young Jennifer Garner

Young Jenna from '13 Going on 30'
Insider | Paramount Pictures

This was quite the lucky break for Allen who had no acting experience at the time.

Garner and Allen collaborated again in the rom-com, 'Ghosts of Girlfriends Past.'

Same as before, she played a younger version of Garner's character. Now, you can find Allen being completely herself on social media.

Although, she has been known to film herself in the famous 13 Going on 30 dress!

2. The title of '10 Things I Hate About You' was inspired by a real-life diary entry from co-writer Karen McCullah

Heath Ledger in '10 Things I Hate About You'
Giphy |

“I had a boyfriend named Anthony ... I made a list called 'Things I Hate About Anthony," she said in an interview.

3. Rachel McAdams and Ryan Gosling hated each other during the first half of filming 'The Notebook'

Noah and Allie about to kiss in rain
Diply | New Line Cinema

At one point, Ryan even tried to replace Rachel! It seems hard to believe now, considering their chemistry in the film and the fact that they dated off-screen for four years.

4. Richard Gere only accepted to be in 'Pretty Woman' because of Julia Roberts

Richard Gere and Julia Roberts holding a jewelry case
Giphy |

Given the subject matter, the actor was wary about the role. But after meeting Julia and receiving a Post-It note from her that said, "Please say yes," he agreed.

5. Kate Hudson improvised a lot of the lines in 'How to Lose a Guy in 10 Days'

Kate and Matthew looking at a photo album
EW | Paramount Pictures

An example of this was when Andie smothered Ben with kisses after he wasn't exactly pleased with their new dog.

Another hilarious example was the lines she said during the movie theatre scene.

6. Brendan Fraiser was supposed to play Jennifer Lopez's love interest in 'The Wedding Planner'

Brendan Fraiser smiling
Giphy |

Four weeks before production started, The Mummy actor dropped out, leaving the crew scrambling.

"We were like, uh-oh," screenwriter Mike Ellis said in an interview with Entertainment Weekly.

This next option was Matthew McConaughey, who was reluctant.

"Adam [Shankman, the director] drove to Matthew McConaughey’s house and begged for him to do it," he concluded. "And he did." Thankfully he did, as it's one of the sweetest rom-coms!

7. 'Overboard' is based on a true story

Kurt Russell and Goldie Hawn in Overboard
The NYT | MGM

Yep, the story about a woman who falls overboard and gets amnesia is true.

According to a New York Times article from 1980, an unidentified woman with amnesia washed ashore in Florida. She was later identified as Cheryl Tomiczek and was reunited with her family.

8. Meg Ryan and Billy Crystal almost weren't in 'When Harry Met Sally'

Harry and Sally kneeling down
Refinery29 | Columbia

While it's hard to imagine anyone else doing that infamous diner scene (you know the one), Sally's character was almost played by Susan Dey, Elizabeth Perkins, Elizabeth McGovern, and Molly Ringwald.

Harry's role also had a shortlist.

Harry and Sally walking in When Harry Met Sally
Giphy | Coolidge Corner Theatre

This includes Albert Brooks, Tom Hanks, and Michael Keaton. Casting definitely got their roles right in the first place, as both Meg and Billy were perfect! It's still considered one of the best romantic movies of all time.

9. Jennifer Grey had "zero chemistry" with her 'Dirty Dancing' co-star, Patrick Swayze

Johnny and Baby dancing on floor
IMBd | Vestron Pictures

In an interview with People, she explained that they were forced to be together. "And our being forced to be together created a kind of a synergy, or like a friction."

10. 'Clueless' is based on real-life events

While the film is loosely based on Jane Austin's Emma, it also draws inspiration from the family life of writer-director, Amy Heckerling.

Turns out, her grandparents got married to each other, despite being stepbrother and stepsister.

12. Emma Stone didn't perform the 'Dirty Dancing' lift scene in 'Crazy, Stupid, Love'

Ryan Gosling pinching Emma Stone's nose
Giphy |

Since she broke both of her arms in a gymnastics accident when she was young, she had to have a body double during her lift scene with Ryan Gosling.

13. Dustin Hoffman was never supposed to make an appearance in 'The Holiday.'

Dustin Hoffman holding a DVD
The List Love | Columbia Pictures

He only made an appearance since he was around during the movie store scene.

His cameo had a cool layer since Miles picked up a copy of The Graduate and began to sing Simon and Garfunkel’s “Mrs. Robinson.”

14. 'This is 40' almost gave an update to 'Knocked Up'

Couple looking unhappy at dinner table
Film School Rejects | Apatow Productions

Since This Is 40 is basically the sequel to Knocked Up, Apatow wanted to give viewers an update on Seth Rogen and Katherine Heigl's characters.

If he did, it would have shown Rogen as a single dad.

15. Matthew McConaughey almost didn't get the part in 'How to Lose a Guy in 10 Days'

Matthew speaking in How to Lose a Guy in 10 Days
Giphy |

At first, they thought he was too old for Kate since Matthew was 33 and she was 23.

But it never bothered Kate since she had been married to Black Crowes’ singer Chris Robinson at the time, who is older.

16. One scene almost made Mark Ruffalo exit '13 Going on 30'

This is the dancing scene where Jennifer Garner's character dances to Michael Jackson's "Thriller." In an interview with Black Film, he said, "I literally read it and I'm like, 'I can't do this movie. I can't get up and do those scenes.'"

So when Jennifer dragged him out on the floor, she was literally dragging him out on the floor.

"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."