Epictetus, Discourses Book IV Chapter 7, “On Freedom From Fear”
And, for this reason, if he thinks that his good and his interest be in these things only which are free from hindrance and in his own power, he will be free, prosperous, happy, free from harm, magnanimous pious, thankful to God for all things; in no matter finding fault with any of the things which have not been put in his power, nor blaming any of them. But if he thinks that his good and his interest are in externals and in things which are not in the power of his will, he must of necessity be hindered, be impeded, be a slave to those who have the power over things which he admires and fears; and he must of necessity be impious because he thinks that he is harmed by God, and he must be unjust because he always claims more than belongs to him; and he must of necessity be abject and mean.
What hinders a man, who has clearly separated these things, from living with a light heart and bearing easily the reins, quietly expecting everything which can happen, and enduring that which has already happened? “Would you have me to bear poverty?” Come and you will know what poverty is when it has found one who can act well the part of a poor man. “Would you have me to possess power?” Let me have power, and also the trouble of it. “Well, banishment?” Wherever I shall go, there it will be well with me; for here also where I am, it was not because of the place that it was well with me, but because of my opinions which I shall carry off with me: for neither can any man deprive me of them; but my opinions alone are mine and they cannot he taken from me, and I am satisfied while I have them, wherever I may be and whatever I am doing. “But now it is time to die.” Why do you say “to die”? Make no tragedy show of the thing, but speak of it as it is: it is now time for the matter to be resolved into the things out of which it was composed. And what is the formidable thing here? what is going to perish of the things which are in the universe? what new thing or wondrous is going to happen? Is it for this reason that a tyrant is formidable? Is it for this reason that the guards appear to have swords which are large and sharp? Say this to others; but I have considered about all these thins; no man has power over me. I have been made free; I know His commands, no man can now lead me as a slave. I have a proper person to assert my freedom; I have proper judges. Are you not the master of my body? What, then, is that to me? Are you not the master of my property? What, then, is that to me? Are you not the master of my exile or of my chains? Well, from all these things and all the poor body itself I depart at your bidding, when you please. Make trial of your power, and you will know how far it reaches.
Whom then can I still fear?
Dave Grohl counters:
Although Grohl counters that the philosophy of Stoicism could easily crumble when actually confronted with the events in life, Epictetus would not disagree. Throughout his Discourses, he laments the students who come to study Stoic thought to learn it, but not to live it, and he acknowledges that it is difficult and requires discipline and training.
So I think Epictetus and Mr. Grohl are actually in agreement here.