21 Behind-the-Scenes Secrets of The Devil Wears Prada

​It's been 10 years since The Devil Wears Prada first hit theaters, but it's still impossible to forget Meryl Streep's intimidating glare or Anne Hathaway's stunning fashion transformation. In honor of the big day, here are 20 behind-the-scenes facts about everyone's favorite rags-to-Chanel comedy.​

1. To prepare for the role, Anne Hathaway interned at Christie's Auction House​ in order to get office experience.

2. Meryl Streep doesn't raise her voice in the movie, a decision she said is partly inspired by Clint Eastwood. "He never raises his voice on the set, and there's no one more intimidating," she said on ​The View​.

3. Stanley Tucci was cast as Nigel only a few days before shooting began. "I kind of had to figure out who he was as we went along," he said.

4. Anne Hathaway said she was nervous about being "accused of being addicted to makeover movies" after already having done ​The Princess Diaries​, but she didn't care because she got to work with Meryl Streep.

5. Emily Blunt added this bit to the movie after seeing someone else do it in real life:

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"I thought I'd just throw it in, and the director really liked it so we kept it," Emily said.

6. Before shooting, Meryl Streep told Anne Hathaway not to lose any weight for the part — and to eat a hamburger. Wise words.

7. Meryl Streep was so good in her character that she literally made Anne Hathaway feel sick during takes. ​

8. Producers later auctioned off the movie's costumes to benefit breast cancer research, Dress For Success, and Equality Now​.

9. Miranda's townhouse belonged to a real-life friend of a producer, because they had trouble finding an apartment for the film.

10. Fox bought the rights to the film before the book was in stores. They saw only the first 100 pages and an outline. ​

11. In real life, Meryl Streep and Stanley Tucci are charades partners every year at a Christmas party. "We've been at each other's throats like married people for a really long time, many years​," Meryl told The Huffington Post in 2010.

12. When Meryl Streep appeared on ​The View​ to promote the movie, she still hadn't seen the ending​.

13. Anna Wintour reportedly attended the movie premiere, and according to a statement issued by her spokesman, thought the movie was "entertaining." "It was satire," said the spokesman. "What's not to like?"

14. Anna later called the movie "fiction." In a somewhat uncomfortable interview on the Late Show with David Letterman in 2009, David asked her about the movie and her thoughts on being the titular "devil." Her reply? "I seem to remember that actually the movie was fiction, and we really like fiction at Vogue."

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15. Conspiracy theorists believe Anna threatened to blacklist participating designers from ​Vogue​. In a behind-the-scenes interview, producer Wendy Finerman said that many people they hoped to get in the film weren't cooperating as much as they had hoped. "Some of them were a little scared about what we were doing and the commentary we were making about fashion," she said.

16. Only one designer, Valentino Garavani, actually appeared as himself in the movie. He even designed the gown Meryl Streep wears to the gala. "Just to be in a film, just with a little cameo with Mrs. Streep for me is a great, great honor," he said.

17. Lauren Weisberger, the author of the original book, claimed no Condé Nast publication covered her book. In an interview with the ​Daily Mail​, she said, "The book was getting so much hype and so much publicity, but not a single Condé Nast publication mentioned a word — not my name, the title, anything, and that pretty much told me where they stood on that."

18. Lauren makes a brief appearance in the movie. You can see her for a couple seconds on the train where Miranda's twins are reading their new Harry Potter manuscripts.

19. The character of Emily was rumored to be based on Plum Sykes, a writer and editor at ​Vogue​. Wintour stated in a ​New York Times ​piece that Plum ''lives the ideal Vogue life,'' and that she's the ''quintessential Vogue girl.''

20. Nigel's character was rumored to be inspired by Simon Doonan, creative ambassador-at-large for Barneys New York. Simon himself was even asked to audition, but the part was given to Stanley Tucci days later. He suspected that he was used as free research for Stanley to play him. In 2013 Simon told Women's Wear Daily that the audition was "a charade" and "nothing more than a carefully orchestrated piece of unpaid research. We gays had been dragged in to swish it up — on camera no less — for the delectation of some precast, overpaid straight actor."

21. According to ​Variety​, Rachel McAdams turned down the role of Andy multiple times because she wanted "to step away from mainstream material​."