Hearts, not minds
What have our feelings got to do with what we believe? Short answer: everything. In fact, when you think you’re having a rational debate, you’re probably not engaging with the other person’s brain, but their emotions. And the stronger the beliefs are held, the greater is the underlying emotion.
Our emotions are the residues from any experience we had that may have caused upset, pain or even trauma. More exactly, they are experiences that we only partially understood in the first place because they were witnessed entirely from our own personal viewpoint.
These emotions colour our world, and they form the lens through which we see everything. Anything that reinforces that view is immediately acknowledged; the thousands of things that happen every week that challenge our world view are discarded, or not even seen in the first place.