Our desires and aversions are mercurial rulers. They demand to be pleased. Desire commands us to run off and get what we want. Aversion insists that we must avoid the things that repel us.
Typically, when we don’t get what we want, we are disappointed, and when we get what we don’t want, we are distressed.
If, then, you avoid only those undesirable things that are contrary to your natural well-being and are within your control, you won’t ever incur anything you truly don’t want. However, if you try to avoid inevitabilities such as sickness, death, or misfortune, over which you have no real control, you will make yourself and others around you suffer.
Desire and aversion, through powerful, are but habits. And we can train ourselves to have better habits. Restrain the habit of being repelled by all those things that aren’t within your control, and focus instead on combating things within your power that are not good for you.
Do your best to rein in your desire. For if you desire something that isn’t within your own control, disappointment will surely follow; meanwhile, you will be neglecting the very things that are within your control that are worthy of desire.
Of course, there are times when for practical reasons, you must go after one thing, or shun another, but do so with grace, finesse, and flexibility. From Epictetus: The Art of Living by Sharon Lebell
Do not spoil what you have
by desiring what you have not;
remember that what you now have
was once among the things you only hoped for.
Epicurus