It is true that a mathematician who is not also something of a poet will never be a perfect mathematician.

God, grant me the serenity to accept the things I cannot change, the courage to change the things I can and the wisdom to know the difference.

Le mal se fait sans effort, naturellement, par fatalité; le bien est toujours le produit d’un art.

Als de melk overkookt, stinkt de stoof.

I do not think there is any other mental strain comparable to the exertion to which a tournament game subjects the chess master. Working at what seemed to me the most difficult mathematical problems has never exhausted me nearly as much as playing in a chess tournament; and of all intellectual applications mathematical work is surely the hardest. That is why physical fitness is a most important factor in tournament chess and why young players, whose brains can stand the poisons of fatigue much longer than those of older players have a great advantage.