Jimmy Fallon decided to test Mandy Moore on her knowledge!
It's been 16 years since she starred in A Walk To Remember.
Moore said that they never expected that movie to touch people in the way that it did.
She also said "I'm slightly flabbergasted that, the sort of things in my career that I'm most known for are making people cry."
Moore also plays Rebecca Pearson on the hit TV Show 'This Is Us'
Fallon decided to quiz her on lines from both roles.
He would do a dramatic reading of one of her or her co-stars lines and the actress had to guess where the line came from!
Of course, she nailed it!