The reader wants to see something happen between pages one and four hundred, and nothing happens if the characters don't change.
Terry BrooksThe unicorns were the most recognizable magic the fairies possessed, and they sent them to those worlds where belief in the magic was in danger of falling altogether. After all there has to be some belief in magic- however small- for any world to survive.
Terry BrooksI might add that you change as a person as you grow older, so you change as a writer, too.
Terry Brooks