ENCINITAS (AP) — Dr. Spencer Johnson, whose book “Who Moved My Cheese?” sold 25 million copies and became a business and self-help phenomenon, has died. Johnson’s executive assistant Nancy Casey said Saturday that he died Monday of complications from pancreatic cancer in the San Diego-area city of Encinitas. “Who Moved My Cheese?” was a slim, 94-page fable on the need to embrace change that was derived from a story Johnson had told at parties and used in speeches.