I know that she said it's about getting rid of your childhood, or something weird like that, but I always thought that it was about drugs. This girl couldn't handle the tragedies in her life, so she ran to drugs. (you built up a world of magic, because your real life was tragic). The woman on the outside the whole time is warning her, "be sure to keep a firm grasp on reality while you're messing with this stuff, or you're going to get hurt". (keep your feet on the ground while your head's in the clouds)(. Brick by boring brick, or the wolf's gonna blow it down). Then the girl gets hurt, and the woman starts trying to convince the girl. "Go get your shovel! Go get everything you have, and we'll get rid of these drugs that you run to, cuz they're wrecking your life!"(chorus). Eventually the woman says "Well, I can't draw you out of the magic world that only you reside in. I choose to believe in the things I can see". That was my interpretation. What do you think? I love this song!