Life presents itself first and foremost as a task: the task of maintaining itself... If this task is accomplished, what has been gained is a burden, and there then appears a second task: that of doing something with it so as to ward off boredom, which hovers over every secure life like a bird of prey.
Thus the first task is to gain something and the second to become unconscious of what has been gained, which is otherwise a burden.
That human life must be some kind of mistake is sufficiently proved by the simple observation that man is a compound of needs which are hard to satisfy; that their satisfaction achieves nothing but a painless condition in which he is only given over to boredom; and that boredom is a direct proof that existence is in itself valueless, for boredom is nothing other than the sensation of the hollowness of existence. For if life, in the desire for which our essence and existence consists, possessed in itself a positive value and real content, then would be no such thing as boredom: mere existence would fulfill and satisfy us. As things are, we take no pleasure in existence except when we are striving after something - in which case distance and difficulties make our goal look as if it would satisfy us (an illusion which fades when we reach it)- or when engaged in purely intellectual activity, in which case we are really stepping out of life so as to regard it from outside, like spectators at a play.
Even sensual pleasure itself consists in a continual striving and ceases as soon as its goal is reached. Whenever we are not involved in one or other of these things but directed back to existence itself we are overtaken by its worthlessness and vanity and this is the sensation called boredom.
-- Arthur Schopenhauer