I think, in terms of truths that "set one free," there is a high probability of being in bondage to some delusion or malformed anxiety, and that the wrenching effect of having to overturn a lot of one's prior beliefs is quite likely to have some anger component, even if only at whatever forces kept one in ignorance previously. In many cases it means coming to terms with the degree to which one had been used and manipulated up until the new perspective arrived. At least this mirrors my experience leaving the church, as well as in some other emotionally loaded topics.