Quote: Intelligence And Work-Life Balance

This is a quote from Douglas Adams' "The Hitchhiker's Guide To The Galaxy":

[..] 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 - while 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.

What if the dolphins were right?