The more tightly held the belief is, the more your brain holds on to this confirmation bias to protect you from having to rethink your entire belief system. So if we’re talking about a core belief like “other people’s perceptions of me determine my worthiness and lovability,” trying to brainstorm proof that “other people’s opinions of me have no impact on my worth” is going to feel like slamming your head against a brick wall repeatedly, and your brain will go “I have no proof, I can never believe this!” Being aware of the bias and noticing it happening makes it much easier to change, and to not take everything my brain tries to insist upon so seriously. And then we can treat your brain much like a stubborn animal, and build up neuroplasticity by starting to notice the evidence that we had previously discounted. 

Lizard brain is running programs constantly under the surface based on all of my socialization, personal experiences, nervous system states, and a whole bunch of shortcuts to help me process the world. And if I never listen to those programs, I don’t have the chance to change them.