Of all the mythical figures we know and love, the Tooth Fairy seems to have the most elusive backstory. Where did she come from, and why the heck do we put our teeth under our pillows for her to find?! Thankfully, a woman named Rosemary Wells made it her mission to track the source of all things related to the Tooth Fairy. And surprisingly, it all started with a French mouse. Intrigued?? We were, too.