I think this is a very important point that is not addressed in the article. The article basically describes avoiding scar tissue as resolving conflicts so there is "zero lingering animosity". And sometimes (actually quite often, I think), only one person of the two in the relationship is prone to feeling any animosity about how a particular conflict got resolved. And in most (if not all) such cases, the best way to avoid the scar tissue is exactly what you say: let it go. Is it really worth feeling even a little smidgen of animosity towards this person, with whom you have a relationship lasting many years or decades, because of this one little thing? At the very least I think one needs to ask oneself that question, before embarking on the kinds of conflict resolution that the article describes.