1. The director, Nick Cassavetes, cast Ryan Gosling as Noah because he wasn't handsome. He actually invited Ryan over to give him the news that he got the part and told him, "I want you to play this role because you're not like the other young actors out there in Hollywood. You're not handsome, you're not cool, you're just a regular guy who looks a bit nuts."
2. Ryan wore brown contacts for filming. Since older Noah was portrayed by James Garner and he had brown eyes, Ryan had to wear brown contacts to cover up his blue eyes.
3. The movie was filmed in reverse. All the older Allie and Noah scenes (with Rachel McAdams and Ryan Gosling) were filmed first. Ryan then had to lose 20 pounds of muscle during his Christmas vacation and shave off his older Noah beard to transform into the younger, fresh-faced Noah who wooed Allie on the Ferris wheel.
4. The famous boat scene almost didn't have birds. The scene where Noah and Allie go out on the lake for a romantic boat ride and gorgeous birds surround them? Well, producers at New Line Cinema said getting those birds to stay on the lake wouldn't be possible. But instead of giving in to the producer's pressure to cut the scene, director Nick Cassavetes found himself some hatchlings and raised them beside the lake so when it came time to film, they'd feel comfortable on the lake. And obviously it worked!
5. Justin Timberlake and Britney Spears were considered for the lead roles.
6. Ryan and Rachel didn't get along. Yep, despite Noah and Allie's intense chemistry on screen, Ryan and Rachel couldn't stand each other behind the scenes. They fought so much that Ryan actually asked for another woman to come and run lines with him during breaks, and Nick finally had to hold an intervention. The director said, "We went into a room with a producer; they started screaming and yelling at each other. I walked out. [Then] everybody came out like, 'All right let's do this.' And it got better after that." Well, considering they went on to date for two years, things clearly did get better.
7. Ryan Gosling improvised that iconic, passionate line at the end of the movie. You know when Noah confronts Allie at the end of the movie and forces her to come to terms with what she really wants, shouting, "What do you want! What do you want?" Ryan was so committed to his character, he came up with that gem on the spot.
8. James Marsden, who played Allie's fiancée Lon Hammond, thought the movie was going to be bad. He said, "I thought The Notebook was going to be a schmaltzy Movie of the Week type thing".
9. "The Notebook" is Ryan Gosling's most successful film. Despite the fact that the movie came out back in 2005 and Ryan's gone on to star in major films like "Drive" and "Crazy, Stupid, Love" with Emma Stone, as of 2012, his most financially successful film is still "The Notebook", having made $105 million, when adjusted for inflation.
10. Ryan Gosling built the table in the dinner scene. Ryan decided to go method for his role as Noah and spent two months doing Noah things, like living in Charleston, South Carolina, and building furniture. It was nice the set designer featured some of his hard work in the film.
11. Rachel McAdams had less than a day to prepare for her audition. She received her script for the movie the night before her audition when she happened to be at another movie's premiere! That only makes the fact that she beat out the likes of Reese Witherspoon and Jessica Biel with her flawless audition.
Source: Redbookmag