Do you remember a time in your life when you wanted to be something like a unicorn, and it totally made sense to you. The world had yet to beat you down and shove you into a little labeled box. Infinite possibilities. Unfortunately, reality seems to seep in younger and younger.
So when my daughter dreams of being a unicorn, I don't tell her they don't really exist. I ask her what color hair she's going to have and what they eat for lunch. I want her to enjoy that magic for as long as she can grasp it with both hands.