Something our GM is very good at is not letting classes get stale. By in large, adult red belts & black belts have been exposed to curriculum beyond/far beyond their level. Much of it they do not get the first time around. Then as time goes by the material is circled back around to and most of the time the person sees it from a very different perspective. That little bit of exposure is a great learning tool for people who invest the time. For those that do not nothing is really lost on them from a time investment perspective.