With the help of a frilly dress, tiara, and magic wand, your 3-year-old is transformed into the queen of a magical universe where her hobby horse is a winged unicorn. When you're asked to taste the pink clouds, you agree that they're a lot like bubblegum.

Your son pulls a sheet over his shoulders and runs as fast as he can across the lawn. The air lifts the fabric; your boy's legs leap into the air. "I'm flying, mommy!" the 4-year-old says. He's a superhero, out to save the backyard from dragons lurking behind the bushes and find treasure buried in the sandbox.

Parents of preschoolers have a front row seat to some of the most imaginative theater ever produced. These are the so-called "magic years" - when a child's brain is developed enough to imagine grand stories but not yet complex enough to reason the way adults do and ask, "But can that really happen?"

Here's why imagination is so important and what you can do to foster these magic years.

How Preschoolers View the World

There's a lot that very young children aren't yet able to grasp about the world around them. As a result, they "fill in the blanks" and often make up their own sometimes magical explanations for how things work.

This time, which peaks during the preschool years, was dubbed "the magic years" by child development expert Selma Fraiberg, PhD, in 1959 when she wrote a book of the same name.

Babies use their senses (touch, taste, smell, sight, and sound) to explore their world. As they develop, they begin to understand the basic function of things ("If I push this button, the pony will pop out of the barn!").

Now, as preschoolers, they take this knowledge and combine it with a growing imagination to come up with fantastical ideas about why and how things happen. As kids go through the magic years, fantasy will move to reality as they further fine-tune their understanding of the world.

Take, for example, the vacuum cleaner. A 2-year-old might throw a tantrum because he fears that, just as the dog hair got sucked up off the carpet, he will too. But a year or two later, instead of collapsing into tears, he might pretend he's being chased by the vacuum "monster" - and gain confidence from knowing that it will never get him.

By age 6 or so, children are becoming aware that any fears of being swallowed up by a vacuum are irrational - there's no way your entire body can be sucked up that little tube! - and instead might want to take control and do the vacuuming on their own.

In this situation, the boy used his imagination to help him get over his fears. This scenario is repeated again and again, as the monsters in the closet suddenly disappear with the help of a brain that is beginning to learn how to differentiate between the possible and the impossible.

Pretend play lets kids try out new roles for themselves (like superheroes, princesses, wild animals, or even parents) and allows for creative problem-solving. But it also helps them deal with another hurdle of the preschool years: intense emotions. Baby dolls might be put in "time out" and scolded for actions suspiciously similar to your little one's latest offense. An imaginary friend (who's a bigger troublemaker than your child ever could be) might be conjured up to help your child deal with feelings of guilt and remorse following a moment of lost control, such as hitting a playmate.

Self-control is a tough skill to learn, and pretend play helps kids practice it as well as play out the frustration it creates.

Learn more about the Magic of Play.