CVIII. On the conflict between pleasure and virtue
It is necessary that one grow accustomed to slender fare: because there are many problems of time and place which will cross the path of even of the rich man and one equipped for pleasure, and bring him up with a round turn. To have whatsoever he wishes is in no man’s power; it is in his power not to wish for what he has not, but cheerfully to employ what comes to him. A great step towards independence is a good-humoured stomach, one that is willing to endure rough treatment.
Seneca Epistles 93-124, Translation by Richard Gummere. Loeb Classical Library.