There are more things, Lucilius, likely to frighten us than there are to crush us; we suffer more often in imagination than in reality. I am not speaking with you in the Stoic strain but in my milder style.   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.

Seneca, Letters

https://en.wikisource.org/wiki/Moral_letters_to_Lucilius/Letter_13