John Green is all dressed up for the Christmas episode of the mental_floss List Show! Since you’re watching Christmas movies, you may as well learn some interesting things about them. You know some, others will be new to you. What’s your favorite Christmas film? It’s a Wonderful Life? The Polar Express? Home Alone? Die Hard? Elf? Grumpy Cat’s Worst Christmas Ever? You have hundreds, it seems, to select from.