Usually you can't build a house without an architect doing drawings – there is an intention prior to the existence of the building. But books are made up like sandcastles: you add stuff and knock it down and change it – and, in fact, you didn't even know you were building a castle at first, you thought you were building a garage. Or you were going to have a cave and instead it turned into a garden full of shells.
That's a quote from Allan Ahlberg in this touching and inspiring article about his life and work. Raise in a tough working class family, so shy he couldn't buy a bus ticket, he was working as a grave digger when his boss encouraged him to become a teacher. Read the whole story. It'll brighten your day.