Snippets from the Handbook 5

Remember that the will to get promises attainment of what you will, and the will to avoid promises escape from what you avoid; and he who fails to get what he wills is unfortunate, and he who does not escape what he wills to avoid is miserable. 

If then you try to avoid only what is unnatural in the region within your control, you will escape from all that you avoid; but if you try to avoid disease or death or poverty you will be miserable. 

—Epictetus, The Handbook 2