Similarly, at a NT platform talk given by Peter Hall he was discussing directing Shakespeare plays. Near me was a supercillious man with his glum teenage son who was clearly undergoing Shakespeare Induction and was having it in stereo, with Sir Peter's explanations receiving affirmation and back-up from Father. At one point Hall quoted the opening lines of Merchant of Venice to illustrate pentameter. The man, with eyes closed and a fixed smile, nodded his head in time with the lines, then as Hall said "Those are the opening lines of the Merchant of Venice" the man leaned in to his son and said "Yes, that is correct." I'm sure Hall would've been relieved.
Perhaps the above are Slightly Annoying or Plain Silly Behaviour at a Show.