Some things are in our control and others not. Things in our control are opinion, pursuit, desire, aversion, and, in a word, whatever are our own actions. Things not in our control are body, property, reputation, command, and, in one word, whatever are not our own actions.
Work, therefore to be able to say to every harsh appearance, "You are but an appearance, and not absolutely the thing you appear to be." And then examine it by those rules which you have, and first, and chiefly, by this: whether it concerns the things which are in our own control, or those which are not; and, if it concerns anything not in our control, be prepared to say that it is nothing to you.
When therefore we are hindered, or disturbed, or grieved, let us never attribute it to others, but to ourselves; that is, to our own principles. An uninstructed person will lay the fault of his own bad condition upon others. Someone just starting instruction will lay the fault on himself. Some who is perfectly instructed will place blame neither on others nor on himself.
Don't demand that things happen as you wish, but wish that they happen as they do happen, and you will go on well.