Carol: I agree that it can be constructive to express one's feelings in this sort of context. But I think Troll has a point that "[going] on and on about how ashamed [one] feel[s] about something or keep[s] pointing out the perceived defects of others" slowly evolves from the expression of feelings into the venting of anger and frustration, which is pleasurable. The perversity of that pleasure comes into play when one is satisfied with simply venting one's feelings again and again about the same situation instead of doing anything constructive to change that situation for the better.