Britney Spears auditioned for 'The Notebook.' She's 'glad' she didn't get it

Britney Spears says not getting the lead role of Allie Hamilton in "The Notebook" helped propel her music career.

"'The Notebook’ casting came down to me and Rachel McAdams," the pop star writes in her memoir, “The Woman In Me.” A clip of Spears' audition is circulating online; one clip has 10 million views on X.

Spears notes that the opportunity to share another screen with Ryan Gosling “would have been fun" after they had already co-starred in "Mickey Mouse Club" starting in 1993. But she writes she's "glad" she ultimately "didn't do" the dramatic romance movie.

"If I had, instead of working on my album "In The Zone," I'd have been acting like a 1940s heiress day and night," she writes. Her fourth studio album featured the song "Toxic," which won Spears her first and only Grammy.

Spears says as a new actor, she had trouble distinguishing between herself and her character.

"I'm sure a lot of the problem was that it was my first experience with acting. I imagine there are people in the acting field who have dealt with something like that, where they had trouble separating themselves from a character,” Spears continues.

Spears says she does not plan to cross that line again when acting. “I hope I never get close to that occupational hazard again,” she writes. “Living that way, being half yourself and half a fictional character, is messed up. After a while you don’t know what’s real anymore.”

She's since made on-screen cameos as herself, like in “Jane the Virgin” and Glee.” She played fictional characters in "How I Met Your Mother" and “Will & Grace."

Spears reflects on what is arguably her most famous acting role in the memoir, too. She says that while acting in the 2002 movie "Crossroads," written by Shonda Rhimes, she "became this other person."

"I really became this other person," she said of her portrayal of Lucy, a "good girl," Spears writes, adding that she walked, talked and carried herself differently off-set.

"This is embarrassing to say, but it's like a cloud or something came over me and I just became this girl named Lucy," she describes. "When the camera came on, I was her, and then I couldn't tell the difference between when the camera was on and when it wasn't."

She says her partner at the time, Justin Timberlake, noticed the difference.

"I took it seriously to the point where Justin said, 'Why are you walking like that? Who are you?'"

She writes two had first "connected" while working on "Mickey Mouse Club" in 1993 and go closer when Spears became his band 'N Sync's opening act in 1998.

“We met up when I was on tour and started hanging out during the day before shows and then after shows too,” she writes. “Pretty soon I realized that I was head over heels in love with him — so in love with him it was pathetic. When he and I were anywhere in the same vicinity — his mom even says this — we were like magnets.”

This article was originally published on TODAY.com