For instance, on the planet Earth, man had always assumed that he was more intelligent than dolphins because he had achieved so much — the wheel, New York, wars and so on — whilst all the dolphins had ever done was muck about in the water having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man — for precisely the same reasons.
Douglas Adams (1952-2001) English author, humourist, screenwriter
The Hitchhiker’s Guide to the Galaxy, ch. 23 (1979)