This movie is generally misunderstood because what it really is, isn't about fantasy or about magical worlds, those are merely instruments in the story talking about the people, who often don't know how special they are. It is about finding out that everything that happens in your life will converge at some point in life to make the best or the worst come out.
A somewhat lesser known film from M. Night Shyamalan. This film received unfavorable reviews and it starts slow, but I really liked it. Its a unique mixture of child and adult themes that create a modern mythology. Suspend some disbelief and you'll have some fun.