I usually stop myself because I tend to feel like its some anger and bitterness that is making me want to do it to let the person know how much I suffered from whatever happened regardless of who the blame goes to. But at the same time, I've never been able to express those kind of feelings, so it usually ends up with me trying to engage in a friendly conversation, especially since I don't want to come across as though I'm still dwelling on the past.
Yet at the same time, I've started to develop a mentality of learning to burn bridges and leaving things behind for good and I feel like its hard to do things like that when I'm unwilling to address certain things.