Individualism has a tendency to promote a form of self-preservation, which acts to maintain a person’s subjective, and experiential interpretation of reality despite its fatal errors. This feels liberating, because there is no pressure in it to be influenced, challenged or sanctioned by a normative authority. Despite its appearance, individualism and its fruits are perniciously dogmatic because they prevent a true appraisal of reality and trade it in for a distorted lens. Once living under this invisible dogma for a substantial period of time, a person becomes immune to criticism, and equates their thoughts and feelings with objective reality.
Paradoxically, when exposed to others living under this paradigm, people will maintain their own distorted notion of truth and reality while accepting contradictory claims from others. This is a required to sustain individualism, no matter how foolish it reveals itself to be. This is demonstrated by the phrase “my truth is my truth, and your truth is your truth”.
But it also appears that this framework is in fact penetrable-though often not enough to destroy the whole structure, but enough to resemble a cheesecloth with the holes being the adoption of some highly propagandized communal value that is accepted as being good for its own sake.
Overall I think that individualism is a product of pride and rebellion. People are no longer willing to accept the possibility of their errors, so they delude themselves into believing that their own thoughts, (and physical desires) are the only authority they are accountable to.