People told fairy tales traditionally to teach children valuable lessons about surviving and navigating a dangerous world. For example, if you had a son or daughter who was in the habit of running off with strangers, you might tell them the tale of Bluebeard who seduced and carried young girls off to his castle and then brutally murdered them. But while parents today most definitely want to teach their children to be wary of strangers, perhaps a chilling tale of castles and murder isn't quite the way they want to go about it. Still, stories tend to be an excellent training tool for people of all ages. Parent still tell their children many of the old fairy tales, or at least they show them the Disney movies. However, a number of modern fairy tales have sprung up to teach children about the current world. Stories like,
1. Harry Potter
If you think Harry Potter is a modern fairy tale just because it's about magic, think again. It's not the magical or fantasy aspect that makes something into a fairy tale. Not really. A fairy tale is more than fairies. It's a story that teaches people about the world around them. Harry Potter at its core is not about magic. It's about a young boy making friends and finding his place in the world. That boy also just happens to be the wizardy chosen one destined to defeat the Dark Lord Voldemort who tried to kill him as a baby. There are plenty of fantasy books out there featuring children who learn to become wizards. Harry Potter became a worldwide sensation because it offered more than magic. Children in the real world go through a lot of the same stuff Harry does: bullies, fights with friends, romantic awkwardness, teachers who don't like them. Hearing Harry's story teaches kids how to deal with stuff like that. That's why it's arguably the most popular modern fairy tale.
2. Avatar: The Last Airbender
This entry is about the television show, not the movie. Avatar is again the story of the magic chosen one who has to fight the evil, magic adult and save the world. It also deals with themes of death and loss, growing up, finding one's place in a changing world, romance, duty and responsibility, and flying bison. Children, and adults, love the show because it's a story about people finding themselves in difficult situations that require clever problem solving and don't have easy solutions. It teaches kids that sometimes life is hard and sometimes you lose, but if you do what you know is right, you'll figure it out. It's a story about kids in a fictional place learning lessons that kids in a very real place today need, and that has always been the function of fairy tales.
3. Doctor Who
It's possible that Doctor Who fans skew more toward adults than children, but one thing that makes a fairy tale more than just a story is its timeless quality. Adults use fairy tales to teach children, but people also use them to teach adults. Doctor Who is on the surface a silly science-fiction show about a remarkably human-looking alien with a time machine. Like the other two entries here though, its real themes are about people navigating their way through a world they don't understand, and what could be a more modern lesson than that? Red Riding Hood taught kids to be afraid of wolves because wolves used to be a pretty serious problem. Problems now are very different, and although they might not be as physically dangerous, they are often overwhelming.
All of these modern fairy tales teach people not to be afraid. They teach us that if we use our brains and do what's right, we'll come out on top. They teach us the lessons we need to get by in our world today.