It is our choices ... that show what we truly are, far more than our abilities. Chamber of Secrets.One can have all kinds of beliefs, but if one does not alter one's actions based on the lessons of the past, then what is the point? Unfortunately, the person with whom I was conversing was not a Harry Potter fan, so I could not use that example to persuade him/her that the key would be a change in behavior. Of course, since the cognitive consistency here was so deep, so much more than confirmation bias, the invoking of Harry Potter and JK Rowling could not/would not have an impact.
Just as it was the pursuit of Horcruxes not Hallows, it is the behavior and the decisions that matter. Does that make me a Potter-ite, a believer in Rowling-ism? I don't know. The personal moment of clarity was, of course, combined with extreme frustration.