Don Juan was teaching Carlos (Castañeda)  his personal power, and  said to Carlos...

“Do you think I’m telling you things beyond your personal power ? No, because everything you do, everything you are, is based on your own inner, personal power. If you have enough of this inner power I can whisper one word that will change your life, but if you do not have enough of this inner, personal power, I could tell you the greatest secrets in the world and it wouldn’t make a damn bit of difference.”