The vanity of existence is revealed in the whole form existence assumes: in the infiniteness of time and space contrasted with the finiteness of the … - Arthur Schopenhauer

Man can do what he wills but he cannot will what he wills.

If a big diamond is cut up into pieces, it immediately loses its value as a whole; or if an army is scattered or divided into small bodies, it loses all its power; and in the same way a great intellect has no more power than an ordinary one as soon as it is interrupted, disturbed, distracted, or diverted; for its superiority entails that it concentrates all its strength on one point and object, just as a concave mirror concentrates all the rays of light thrown upon it. Noisy interruption prevents this concentration. This is why the most eminent intellects have always been strongly averse to any kind of disturbance, interruption and distraction, and above everything to that violent interruption which is caused by noise; other people do not take any particular notice of this sort of thing.

Sleep is the interest we have to pay on the capital which is called in at death; and the higher the rate of interest and the more regularly it is paid, the further the date of redemption is postponed.