Epictetus, Golden Sayings 104

You would gladly be a victor at the Olympic games, you say. Yes, but weigh the conditions, weigh the consequences; then and then only, lay to your hand—if it be for your profit. 

You must live by rule, submit to diet, abstain from dainty meats, exercise your body perforce at stated hours, in heat or in cold; drink no cold water, nor, it may be, wine. In a word, you must surrender yourself wholly to your trainer, as though to a physician.

Then in the hour of contest, you will have to delve the ground, it may by chance dislocate an arm, sprain an ankle, gulp down abundance of yellow sand, be scourge with the whip—and with all this sometimes lose the victory. Count the cost—and then, if your desire still holds, try the wrestler's life. 

Otherwise let me tell you that you will be behaving like a pack of children playing now at wrestlers, now at gladiators; presently falling to trumpeting and then to stage-playing, when the fancy takes them for what they have seen. 

And you are even the same: wrestler, gladiator, philosopher, orator all by turns and none of them with your whole soul. Like an ape, you mimic what you see, to one thing constant never; the thing that is familiar charms no more. 

This is because you never undertook anything with due consideration, nor after strictly testing and viewing it from every side; no, your choice was thoughtless; the glow of your desire had waxed cold. . . . 

Friend, think first what it is you would do, and then what your own nature is able to bear. Would you be a wrestler, consider your shoulders, your thighs, your loins—not all men are formed to the same end. 

Think you to be a philosopher while acting as you do? Think you to go on thus eating, thus drinking, giving way in like manner to wrath and to displeasure? 

No, you must watch, you must labor; overcome certain desires; quit your familiar friends, submit to be despised by your slave, to be held in derision by them that meet you, to take the lower place in all things, in office, in positions of authority, in courts of law. 

Weigh these things fully, and then, if you will, lay to your hand; if as the price of these things you would gain Freedom, Tranquillity, and passionless Serenity.