The Hitchhiker's Guide to the Galaxy
Arthur learns that the Earth was actually a giant supercomputer. It was created by another supercomputer, Deep Thought. Deep Thought had been built to give the answer to the "Ultimate Question of Life, the Universe, and Everything".  It gave the answer as "42". The creators of Deep Thought were disappointed and Deep Thought was then instructed to design the Earth supercomputer to determine what the question actually is.