At the beginning of Chapter 21, what does the author say makes a story or narration truly effective?

At the start of Chapter 21, the author reflects on the art of storytelling and what makes it impactful. He posits that a speaker's words are futile if they do not deeply move the listener. An effective narration, in his view, is one that causes the listener to "sway upon hearing them," makes the "hair on the body stand on end," chokes the throat with emotion, and brings "tears of love and joy" to the eyes. He believes narrations that fail to delight the listeners are useless. Following this, he praises Sai Baba's own methods, describing Baba's speech as captivating and His style of instruction as extraordinary, setting a high standard for the stories he is about to tell in Chapter 21.