The ATU system catalogs plots from folktales for cross-cultural comparison. "The Magic Mill" (ATU 565) is a tale type where someone gets a magical grinding mill that cranks out meal or salt or what-have-you, but the mill only listens to its true owner and causes havoc when others try to use it. Why is the ocean salty? Well, a long time ago a magic salt mill fell into a sailor's hands and he unintentionally filled the ocean with salt because he couldn't turn it off. Magic mill go brr? 🤔