I like the concept that students remember most at the beginning of a session, and at the end of the session, and only seem to be interested in humor about the subject matter in the middle of a session. as a result of this knowledge I have implemented a change in my normal routine. I am still experimenting with this adjustment in routine. I do like the repleteness of touching on key comments in a lecture, this seems to work very well for my students, judging from results on quiz
questions presented during follow up at the end of the session.