From Data and Reality:
The thing that makes computers so hard to deal with is not their complexity, but their utter simplicity. … The real mystique behind computers is how anybody can manage to get such elaborate behavior out of such a limited set of basic capabilities. The art of computer programming is somewhat like the art of getting an imbecile to play bridge or to fill out his tax return by himself. It can be done, provided you know how to exploit the imbecile’s limited talents, and are willing to have enormous patience with his inability to make the the most trivial common sense deductions on his own.
The quote comes from the 1st edition, published in 1978, because that’s what I ran across. The link is to the 3rd edition, published last year.