There's only one test of a great children's book, or a great children's film, and that is this: If it can be read or viewed with pleasure by adults, then it has the chance to be a great children's film, or a great children's book.
But maybe it's up in the hills under the leaves or in a ditch somewhere. Maybe it's never found. But what you find, whatever you find, is always only part of the missing, and writing is the way the poet finds out what it is he found.
There really isn't any limit to the number of people who want a piece of you, and it's all important stuff.