Sometime people hold a core belief that is very strong. When they are presented with the evidence that works against that belief, the new evidence cannot be accepted. It would create a feeling that is extremely uncomfortable, called cognitive dissonance. And because it is so important to protect the core belief, they will rationalize, ignore or even deny anything that doesn’t fit in with the core belief.

For example: You think you are an honest person. That is your core belief. But you cheat on your taxes. Cheating on your taxes goes against the idea of you being an honest person. This is a very uncomfortable feeling, the cognitive dissonance. You really want to continue believing that you are an honest person, so you may rationalize that the government “owes” you anyway.

Cognitive dissonance: psychological conflict resulting from incongruous beliefs and attitudes held simultaneously