Might be also that kids generally still can dream, adults lose that ability if untrained. I believe that most of subjects that are touched on in "The Little Prince" are factual.

The other day my wife got into a playground toy car for kids, 3 kids got into, and each was picking a destination while she was driving them. Wooden toy car and pretend motor sounds + an adult pretending to drive them were enough for them to get immersed.