106 Teaching Minds do exactly this: They supply generalizations when a student needs one and cannot come up with one by himself after a prediction that he made has failed.) The generalization that Colby supplied was, more or less: Be enter- taining if you want to attract followers and be listened to. Was he right? Is this a good generalization? The next step in thinking is: Explain your generalization. What this means here is that I needed to understand why this might be true. If possible, one wants to test out the new hypothesis. Fortunately for me, I had many opportunities to speak in public over the next 40 years. I tried many different methods of teaching and lecturing. Enter- taining always works. Colby was right. But I said that one needs to explain why it works. This is my expla- nation: People have trouble paying attention to someone who talks for an hour. Human beings are not built for this. Our ancestors certainly didn’t listen to lectures. People communicate best by asking questions and interrupting. Since this isn’t possible in a lecture, any questions they might ask, they ask themselves and try to answer. While they are thinking about what a speaker says, the speaker keeps on talking. No one can really hear a lecture, in my opinion. So, a good speaker, recog- nizing this, does not try to make the audience do that. He makes them laugh, he paints interesting pictures for them to ponder, he amazes them perhaps, but he does not try to get them to, nor does he expect them to, remember all that he has said. The less content, the more likely they will remember. Colby knew all this. I learned it over time. He jump-started my thinking. By now, this new generalization of mine, together with my expla- nation, is part of my core beliefs. But any belief can be challenged by reality. And, any new belief generates new predictions. So I predicted that if I was funnier when I spoke, people would appreciate what I said more. I also predicted that if I didn’t speak m