When working towards a solution of a problem, it always helps if you know the answer. -Murphy's Laws of Computers
On 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. -HHGTTG
It is impossible to make anything foolproof because fools are too ingenious.