The repressed state of feeling limited by the (often illogical) mores of society into which most people (Americans, at least) seem to enter as they transition toward adulthood. The transition is a gradual process, with the most strongly unaccepted practices (such as public nudity) being eliminated first, but is rarely fully realized until after college when people seem to feel obliged to start "acting like grown-ups". Generally, this means forgetting how to have a good time.

Of course, not everyone falls into this trap. As with all generalizations, there are exceptions.