McAdams, 35, starred opposite Ryan Gosling in the love story, which is hailed as one of the most romantic films of all times.
She was seen blushing, with her head down, when she was shown her 10-year-old audition tape for the film at a TV chat show recently, reported The Huffington Post.
McAdams reads lines from an emotional scene for director Nick Cassavetes and Ryan Gosling in the audition clip.
Though she once called the moment 'the best audition experience I've ever had,' it did not save McAdams from embarrassment, who admitted she was watching the clip for the first time ever.
The film, based on the novel of the same name by Nicholas Sparks, released in 2004.