Don't suffer imagined troubles

There are more things … likely to frighten us than there are to crush us; we suffer more often in imagination than in reality.

What I advise you to do is, not to be unhappy before the crisis comes; since it may be that the dangers before which you paled as if they were threatening you, will never come upon you; they certainly have not yet come.

Accordingly, some things torment us more than they ought; some torment us before they ought; and some torment us when they ought not to torment us at all. We are in the habit of exaggerating, or imagining, or anticipating, sorrow.

It is likely that some troubles will befall us; but it is not a present fact. How often has the unexpected happened! How often has the expected never come to pass! And even though it is ordained to be, what does it avail to run out to meet your suffering? You will suffer soon enough, when it arrives; so look forward meanwhile to better things. What shall you gain by doing this? Time. There will be many happenings meanwhile which will serve to postpone, or end, or pass on to another person, the trials which are near or even in your very presence. A fire has opened the way to flight. Men have been let down softly by a catastrophe. Sometimes the sword has been checked even at the victim’s throat. Men have survived their own executioners. Even bad fortune is fickle. Perhaps it will come, perhaps not; in the meantime it is not. So look forward to better things.  - Seneca, approximately 4 B.C.-65 A.D

In short - don’t anticipate sorrow. Don’t let anxiety and worry get the best of you. Don’t let your worries grow out of proportion to what might actually happen. Don’t let imagination overtake reality. Don’t suffer twice.