"Human life the Stoics appear to have considered as a game of great skill; in which, however, there was a mixture of chance [...] In such games the stake is commonly a trifle, and the whole pleasure of the game arises from playing well, from playing fairly, and playing skilfully. If notwithstanding all his skill, however, the good player should, by the influence of chance, happen to lose, the loss ought to be a matter, rather of merriment, than of serious sorrow. He has made no false stroke; he has done nothing which he ought to be ashamed of; he has enjoyed completely the whole pleasure of the game. [...]

Our only anxious concern ought to be, not about the stake, but about the proper method of playing. If we placed our happiness in winning the stake, we placed it in what depended upon causes beyond our power, and out of our direction. We necessarily exposed ourselves to perpetual fear and uneasiness, and frequently to grievous and mortifying disappointments. If we placed it in playing well, in playing fairly, in playing wisely and skilfully; in the propriety of our own conduct in short; we placed it in what, by proper discipline, education, and attention, might be altogether in our own power, and under our own direction. Our happiness was perfectly secure, and beyond the reach of fortune."

[1] http://www.econlib.org/library/Smith/smMS7.html