“You are to consider that a certain melancholy and often a certain irascibility accompany advancing age: indeed it might be said that advancing age equals ill-temper. On reaching the middle years a man perceives that he is no longer able to do certain things, that what looks he may have had are deserting him, that he has a ponderous great belly, and that however much he may yet burn he is no longer attractive to women; and he rebels. Fortitude, resignation and philosophy are of more value than any pills, red, white or blue.”

“You live in a deranged age - more deranged than usual, because despite great scientific and technological advances, man has not the faintest idea of who he is or what he is doing.”

“By the time he reaches the farm, he is sure that the Bailey he is now is closer to the Bailey he is supposed to be than the Bailey he had been the day before. He may not be certain what any of it means, but for now he does not think that it much matters.”

“There is no man...however wise, who has not at some period in his youth said things, or lived a life, the memory of which is so unpleasant to him that he would gladly expunge it. And yet he ought not entirely to regret it, because he cannot be certain that he has indeed become a wise man...”

“A man doesn't grow old because he has lived a certain number of years. A man grows old when he deserts his ideal. The years may wrinkle his skin, but deserting his ideal wrinkles his soul.”

“I had better say something here about this question of age, since it is particularly important for mathematicians. No mathematician should ever allow himself to forget that mathematics, more than any other art or science, is a young man's game. To take a simple illustration at a comparatively humble level, the average age of election to the Royal Society is lowest in mathematics. We can naturally find much more striking illustrations. We may consider, for example, the career of a man who was certainly one of the world's three greatest mathematicians. Newton gave up mathematics at fifty, and had lost his enthusiasm long before; he had recognized no doubt by the time he was forty that his greatest creative days were over. His greatest idea of all, fluxions and the law of gravitation, came to him about 1666 , when he was twentyfour—'in those days I was in the prime of my age for invention, and minded mathematics and philosophy more than at any time since'. He made big discoveries until he was nearly forty (the 'elliptic orbit' at thirty-seven), but after that he did little but polish and perfect.Galois died at twenty-one, Abel at twenty-seven, Ramanujan at thirty-three, Riemann at forty. There have been men who have done great work a good deal later; Gauss's great memoir on differential geometry was published when he was fifty (though he had had the fundamental ideas ten years before). I do not know an instance of a major mathematical advance initiated by a man past fifty. If a man of mature age loses interest in and abandons mathematics, the loss is not likely to be very serious either for mathematics or for himself.”