Just as a stream flows smoothly on as long as it encounters no obstruction, so the nature of man and animal is such that we never really notice or become conscious of what is agreeable to our will; if we are to notice something, our will has to have been thwarted, has to have experienced a shock of some kind.
Arthur SchopenhauerIf the world were a paradise of luxury and ease, a land flowing with milk and honey, where every Jack obtained his Jill at once and without any difficulty, men would either die of boredom or hang themselves; or there would be wars, massacres, and murders; so that in the end mankind would inflict more suffering on itself than it has now to accept at the hands of Nature.
Arthur Schopenhauer