Sourcery (Discworld, #5; Rincewind, #3)

by Terry Pratchett

“Talent just defines what you do,” he said. “It doesn’t define what you are. Deep down, I mean. When you know what you are, you can do anything.”

“Oh, yes. It’s vital to remember who you really are. It’s very important. It isn’t a good idea to rely on other people or things to do it for you, you see. They always get it wrong.”

Sourcerers never become part of the world. They merely wear it for a while.