It should be explained at this point that modern elevators are strange and complex entities. The ancient electric winch and maximum capacity eight persons jobs bear as much relation to a Sirius Cybernetic Corporation ‘Happy Vertical People Transporter’, as a packet of peanuts does to the entire West Wing of the Sirian State Mental Hospital. This is because they operate on the unlikely principle of defocused temporal perception - a curious system which enables the elevator to be on the right floor to pick you up even before you knew you wanted it, thus eliminating all the tedious chatting, relaxing, and making friends that people were previously forced to do whilst waiting for elevators. Not unnaturally, many lifts imbued with intelligence and precognition became terribly frustrated with the mindless business of going up or down, experimented briefly with the notion of going sideways - as a sort of existential protest - demanded participation in the decision making process, and, finally, took to sulking in basements. At this point a man called Gardrilla Manceframe rediscovered and patented a device he had seen in a history book called a staircase. It has been calculated that his most recent tax bill paid for the social security of five thousand redundant Sirius Cybernetics Workers, the hospitalisation of a hundred Sirius Cybernetics Executives, and the psychiatric treatment of over seventeen-and-a-half-thousand neurotic lifts.

From the Hitchhiker’s Guide to the Galaxy radio series