Seek not that the things which happen should happen as you wish; but wish the things which happen to be as they are, and you will have a tranquil flo… - Epictetus

Continually remind yourself that you are a mortal being, and someday will die. This will inspire you not to waste precious time in fruitless activities, like stewing over grievances and striving after possessions.

There are things that are within our power, and things that fall outside our power. Within our power are our own opinions, aims, desires, dislikes — in sum, our own thoughts and actions.

For I am not everlasting, but a human being, a part of the whole as an hour is a part of the day. Like an hour I must come, and like an hour pass away.