The Princess Diaries (2001)

Not gonna lie, we kind of wish we would have had the chance to see Julie Andrews play Queen Clarice as she was originally written. While Andrews makes Clarice a kindly force of understanding and a very regal queen, Meg Cabot’s “Grandmere” is something else entirely: a chain-smoking, Sidecar swilling, selfish gorgon. The differences between the film and the book don’t stop there—Mia’s (Anne Hathaway) dad is still alive in Cabot’s series of novels, and it takes Mia three books to finally unite with her OTP, Michael Moscovitz (Robert Schwartzman). Both the films and the novels are fizzy, girl-powered escapes; while you have two films to choose from (the second one bearing no resemblance to the original novels), there are 10 original YA Princess Diaries novels and a recent adult addition, The Princess Diaries XI: Royal Wedding. Their epistolary format, allowing readers to feel as if they’re reading Princess Mia’s diary, is an experience only possible on the page.

Forrest Gump (1994)

While many revel in the sentiment and earnestness at the heart of Forrest Gump, its original source material is far more cynical and cold. It’s hard to keep a dry eye when Jenny (Robin Wright) succumbs to her illness, leaving Forrest to raise their son on his own. In the book, she not only survives, but marries another man and has his child. On film, Gump is a decent and honest character, but the book featured a character a bit more rough around the edges—something sanded down with the film’s emphasis on the love story over the secondary fantastical adventures of Gump’s life. Winston Groom disliked the adaptation of his work so much, he began Gump and Co., the book’s sequel, with Forrest telling readers, “Don’tnever let nobody make a movie of your life’s story.”