Joyce Cary

The truth is that life is hard and dangerous; that he who seeks his own happiness does not find it; that he who is weak must suffer; that he who demands love will be disappointed; that he who is greedy will not be fed; that he who seeks peace will find strife; that truth is only for the brave; that joy is only for him who does not fear to be alone; that life is only for the one who is not afraid to die.

It is the tragedy of the world that no one knows what he doesn't know - and the less a man knows, the more sure he is that he knows everything.