Letters 91.18

Imagine that nature is saying to us: “Those things of which you complain are the same for all. I cannot give anything easier to any man, but whoever wishes will make things easier for himself.” In what way? By equanimity. You must suffer pain, and thirst, and hunger, and old age too, if a longer stay among men shall be granted you; you must be sick, and you must suffer loss and death.

Seneca, Letters to Lucilius 91.18, translated by Richard Mott Gummere