Because your own strength is unequal to the task, do not assume that it is beyond the powers of man; but if anything is within the powers and province of man, believe that it is within your own compass also.
When force of circumstance upsets your equanimity, lose no time in recovering your self-control, and do not remain out of tune longer than you can help. Habitual recurrence to the harmony will increase your mastery of it. (6:11)
Marcus Aurelius (121 - 180)
Source: Meditations (Penguin Great Ideas), Pages: 6:11
Letting go all else, cling to the following few truths. Remember that man lives only in the present, in this fleeting instant: all the rest of his life is either past and gone, or not yet revealed. This mortal life is a little thing, lived in a little corner of the earth; and little, too, is the longest fame to come - dependent as it is on a succession of fast-perishing little men who have no knowledge even of their own selves, much less of one long dead and gone.