An embarrassing spelling mistake and 10 other random things you didn’t know about How to Lose a Guy in 10 Days.

When it comes to rom-coms, How To Lose a Guy in 10 Days is one of those feel good comedies that never fails to deliver.

The hit 2003 film, follows magazine writer Andie Anderson (played by Kate Hudson) who's assigned to write an article aptly titled "How to lose a guy in 10 days". But when Andie sets her sights on advertising executive Benjamin Barry (played by Matthew McConaughey) her plan... doesn't exactly go well. 

You see, right before they meet Ben makes a bet with his boss that he can make any woman fall in love with him. Cue love ferns, bad karaoke and a whole lot of "Benny boo-boo-boo".

Watch the trailer for How To Lose a Guy in 10 days and relive all the feels. Post continues below.

But 17 years on from its premiere, there’s a bunch of things you probably didn’t know about the film that we now want to share with you.  

From casting choices to improvised moments, here are 11 surprising behind-the-scenes facts about How To Lose a Guy in 10 Days.

1. The film is based on an illustrated book.

Believe is or not, the film is actually based on a comic book called How to Lose a Guy in 10 Days: The Universal Don'ts of Dating.

In fact, Andie’s two friends, Michele (played by Kathryn Hahn) and Jeannie (played by Annie Parisse) are named after the book's two authors Michele Alexander and Jeannie Long.

Image: Paramount Pictures. 

2. Gwyneth Paltrow was considered for the role of Andie.

We can't imagine anyone playing Andie other than Kate Hudson. But she wasn't the only one considered for the role 

According to the film's producer Lynda Obst, Gwyneth Paltrow was also interested at first. 

However, Hudson ended up landing the role and Paltrow was cast in 2003 film View from the Top.

3. Matthew McConaughey almost didn't get the role because of his age.

Yep, Matthew McConaughey almost wasn't cast either. 

Speaking to Entertainment Weekly, Obst explained she was worried that McConaughey was too old to date Hudson in the film, given their 10 year age gap. 

"[At first] we thought he was old for her... He’s 33, she’s 23," she told the publication. 

But the age gap never bothered Hudson. "I’m married to a 36-year-old, and it’s not like he’s ancient," she said about her now ex-husband Chris Robinson.

4. Some moments in the film were actually improvised.

When it came time to film, director Donald Petrie said he encouraged the actors to improvise on set.

"I'm very sneaky as a director. I'd go over to Kate and say, 'OK, in this next take, don't tell Matthew, but do this'," Petrie told the BBC in 2014.

"She would do it. What's great is that, because they're such consummate professionals, they never break character. They just go with it."

In fact, it was Hudson who came up with the idea to toss the veggie platter at Ben and his friends during the poker game, according to The Hollywood Reporter.

Image: Paramount Pictures. 

5. Anna Wintour helped Kate Hudson prepare for the role.

In order to prepare for the role of a columnist at a women's magazine, Hudson spent a day with Vogue editor-in-chief Anna Wintour. 

She also told Entertainment Weekly that she studied magazines and "tore out all of these how-tos in Cosmo and Glamour" which she usually skips over. 

6. Scenes were filmed in the same office building as Vogue. 

The scenes filmed inside Composer Magazine's offices were actually shot at the Conde Nast building in New York City, which is home to big name publications like GQ and Vogue.

7. Katherine Heigl made a *brief* appearance in the film. 

In a blink-and-you-miss-it moment, actress Katherine Heigl makes a short appearance in How to Lose a Guy in 10 Days.

If you look closely at the magazines in the beginning of the film, you'll spot Heigl as one of the models on the covers of Composure Magazine.

Image: Paramount Pictures. 

8. There's a spelling error in the film's opening credits.

Speaking of magazine covers, there's a pretty obvious spelling mistake on one of the Composure covers at the start of the film. 

One of the headlines reads "loose your belly" instead of "lose your belly".

The fact that "lose" is also in the film's title makes the mistake that much more awkward. 

Image: Paramount Pictures. 

9. Kate Hudson can actually sing. 

Don't believe the tone-deaf karaoke performance of "You're So Vain", Hudson really can sing.

The 41-year-old even guest-starred on Glee as college dance teacher Cassandra July between 2012 and 2013. 

She's also posts videos of her singing (and working out) on Instagram. 

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10. The diamond necklace Andie wore in the film costs millions.

Towards the end of the film, Ben and Andie attend the "Frost Yourself" gala where Andie is given a diamond necklace to wear. 

It turns out that necklace was very much real. And it comes with an eye-watering price tag. 

According to Katie Callahan & Co, the 80-carat diamond pendant necklace was created by Harry Winston and was later sold for $5 million after the film. 

And that's not all. Over $14 million worth of jewels were also reportedly loaned for the scene. 

Image: Paramount Pictures. 

11. It wasn't the only time Kate Hudson and Matthew McConaughey played a couple. 

Five years after playing Ben and Andie in How to Lose a Guy in 10 Days, Hudson and McConaughey reunited to play a recently divorced couple in the 2008 film Fool’s Gold. 

There's certainly no denying the pair have chemistry.

For more things you didn't know about other movies, check these out:

• Ryan Gosling "wasn't handsome" and 11 other things you didn't know about The Notebook.
• Subtle cameos and a very different plot: 14 things you didn't know about The Devil Wears Prada.
• A body double and a hidden ear piece: 14 things you didn't know about The Parent Trap.
• Improvisation and Blake Lively's failed audition: 12 things you never knew about Mrs. Doubtfire.

How to Lose a Guy in 10 Days is available to watch on Stan. 

Feature Image: Paramount Pictures.