I've never wanted to be a witch, but an alchemist, now that's a different matter. To invent this wizard world, I've learned a ridiculous amount about alchemy. Perhaps much of it I'll never use in the books, but I have to know in detail what magic can and cannot do in order to set the parameters and establish the stories' internal logic.
J. K. RowlingSuch loyalty is admirable, of course,” said Scrimgeour, who seemed to be restraining his irritation with difficulty, “but Dumbledore is gone, Harry. He’s gone.” “He will only be gone from the school when none here are loyal to him,” said Harry, smiling in spite of himself.
J. K. RowlingThis liberating discovery enables me to proceed without any fear that I might inadvertently influence you to abandon promising careers in business, law or politics for the giddy delights of becoming a gay wizard.
J. K. RowlingThe thing about growing up with Fred and George," said Ginny thoughtfully, "is that you sort of start thinking anything's possible if you've got enough nerve.
J. K. Rowling