Do you wish to be invincible? Then don’t enter into combat with what you have no real control over. Your happiness depends on three things, all of wh… - Epictetus

Your happiness depends on three things, all of which are within your power: your will, your ideas concerning the events in which you are involved, and the use you make of your ideas.

Whatever moral rules you have deliberately proposed to yourself abide by them as they were laws, and as if you would be guilty of impiety by violating any of them. Don't regard what anyone says of you, for this, after all, is no concern of yours. How long, then, will you put off thinking yourself worthy of the highest improvements and follow the distinctions of reason? You have received the philosophical theorems, with which you ought to be familiar, and you have been familiar with them. What other master, then, do you wait for, to throw upon that the delay of reforming yourself?... Let whatever appears to be the best be to you an inviolable law.(50).

Remind yourself that your precious one isn't one of your possessions, but something given for now, not forever.

the World turns aside to let any man pass who knows where he is going.