The process of learning necessarily involves emotion. The stronger the emotion, the deeper the memory, and the better the learning. If we have learned some concepts, and these concepts have been reinforced by emotions associated with them over a long period of time, then it becomes very hard to unlearn them.
The mechanism for how emotion results in storage of memory is complex, like everything else in the brain. The picture below is taken from the review, “Emotional modulation of Learning and Memory: Pharmacological Implications” in Pharmacol. Rev. 2017 Jul;69(3):236-255. doi: 10.1124/pr.116.013474.” It summarizes some of the basic mechanisms by which emotion results in deeper storage and recall.
The point is that if we have learned something over several years, when confronted with something that is contrary to our knowledge, we can become angry or emotional. This is independent of the preponderance of evidence, ideas or arguments that someone may offer to us. It is also independent of the sincerity and/or competence of the person who is trying to help us.
Unlearning a concept requires an emotional commitment to 1) be open-minded to alternatives, 2) make an effort to understand opposing views, 3) change one’s mind when faced with a superior argument and 4) re-learn a new, and frequently opposing concept. This is quite challenging even for the simplest things. This is why breaking bad habits like smoking or overeating is so difficult.
But when learning new concepts implies changing one’s whole worldview, people become very stubbornly resistant to change. They will rationalize, and justify, and further rationalize- anything- but face the truth. Adults become like children in such situations. They throw tantrums, become angry and, well, act in surprising ways. Of course, it is not their fault really. It is the basolateral amygdala at work. This is why unlearning is much harder than learning.
In the field of uttamā bhakti, the commitment ought to be to śāstra first, and then to individuals because they maintain fidelity to śāstra and teach self-consistent concepts. śāstra is the very source of all knowledge of bhakti, and of Kṛṣṇa. One must be attached to it emotionally, and this faith is called śāstriya śraddhā. It is not optional.
When the emotional commitment is to individuals over and above śāstra, then one becomes vulnerable to getting misguided, can get trapped into personality cults, and is then unable to practice uttamā bhakti in a healthy frame of mind. The goal of uttamā bhakti is uttamā bhakti, but one’s intentions become distorted and waylaid in myriad activities that actually taken one away from uttamā bhakti. Such a person will stubbornly resist changing old, erroneous concepts. This becomes more pronounced particularly in older individuals who have accumulated a lifetime of emotions associated with a particular viewpoint. So strong is their emotional commitment, that they can go to any lengths to defend it, and also to convince others.
It is therefore critical to find the right guru! Then one only has to learn, and not face the prospect of unlearning copious amounts of wrong concepts later in life. This is also why clarity in teaching is crucially important, and why being a guru is such an enormous responsibility.