In his case, he was leading into a discussion of the rules of rhyming schemes and such, but he also admitted that the lesson is applicable to a lot of other things. Case in point: using the fourth wall in roleplaying.
MMOs lean on the fourth wall all the time, some more or less than others. But roleplaying generally steers clear of it because leaning on it too heavily can really screw with the overall roleplaying atmosphere. So let's talk a little bit about what the fourth wall is and how you can use it with care to enhance roleplaying rather than damage it.