"Gary Dahl was out one evening having a few drinks with his buddies when the conversation turned to pets. Dahl, a California advertising man, joined in by claiming he had a pet rock—an ideal pet with a great personality that was easy and cheap to care for. His friends laughed at the idea. Little did they know that a pop-culture fad was about to be born.
It was April 1975, and Dahl's initial idea was to write a book—The Care and Training of Your Pet Rock—a step-by-step guide to having a happy relationship with your geological pet. He spent the next few weeks writing the book, which included instructions on training the Pet Rock to do tricks, such as roll over..."