A Joke Every 10 Minutes

Just went to what appeared to be a very standard physchemology talk for a general audience. The speaker was not flashy or showy, and the material easily could have been boring. However, he had an excellent joke about every 10 minutes or so, effectively "resetting" the room. It was not boring, and everyone learned something, even those working in the same field. The timing was regular enough that I believe this was an example of a good speaker/teacher who was made and not born. He effectively missed the zoning out that occurs 10-15 minutes into a typical lecture. Now, in class, I try to do that with activities, but I've almost never put breaks or jokes into presentations out of class. I'll have to consider this when I prep my next formal presentation.