If you want your family and friends to live forever, you’re a fool, because you’re trying to control what you can’t, and insisting that what’s up to others be within your will. Likewise, if you want your subordinate to perform perfectly, you’re a fool, because you’re deciding that his attitudes must be subject to yours. If you want to avoid disappointment, that you can do. Pay attention to what’s really up to you. Your master is whoever controls the things you want, or want to avoid. If you want to be free, don’t wish for anything, or try to avoid anything, that others control; otherwise you’re a slave.