Writing for adults, you have to keep reminding them of what is going on. The poor things have given up using their brains when they read. Children you only need to tell things to once.
It does seem that a fantasy, working out in its own terms, stretching you beyond the normal concerns of your own life, gains you a peculiar charge of energy which inexplicably enriches you. At least, this is my ideal of a fantasy, and I am always trying to write it.
