One of the books I read obsessively as a child is The Restaurant at the End of the Universe. Excerpt below that is all the explanation you need:
“Yeah, yeah,” said Zaphod as the elevator doors opened.
“Hello,” said the elevator sweetly, “I am to be your elevator for this trip to the floor of your choice. I have been designed by the Sirius Cybernetics Corporation to take you, the visitor, into these offices. If you enjoy your ride, which will be swift and pleasurable, then you may care to experience some of the other elevators which have recently been installed in the offices of the Galactic tax department, the Boobiloo Baby Foods and the Sirian State Mental Hospital, where many ex-Sirius Cybernetics Corporation executives will be delighted to welcome your visits, sympathy and happy tales of the outside world.”
“Yeah,” said Zaphod, stepping into it, “what else do you do besides talk?”
“I go up,” said the elevator, “or down.”
“Good,” said Zaphod, “we’re going up.”
“Or down,” the elevator reminded him.
“Yeah, okay, up please.”
There was a moment of silence.
“Down’s very nice,” suggested the elevator hopefully.
“Oh, yeah?”
“Super.”
“Good,” said Zaphod, “now will you take us up?”
“May I ask you,” inquired the elevator in its sweetest, most reasonable voice, “if you’ve considered all the possibilities that down might offer you?”
Zaphod knocked his head against the inside of a wall. He didn’t need this, he thought to himself, this of all things he had no need of. Most of all he didn’t want to be standing in an office block arguing with an elevator.
“Like what other possibilities?” he said wearily.
“Well,” the voice trickled on like honey on biscuits. “there’s the basement, the microfiles, the hearing system… er…” It paused.
“Nothing particularly exciting,” it admitted, “but they are alternatives.”
“Holy Zarquon,” muttered Zaphod, “did I ask for an existential elevator?”