Listener question: How do beliefs get believed?

Listener question: I've just finished reading 'Sane'.  A challenging read for me to stick with if I'm being honest.  I found myself constantly wanting to run ahead to the 'how to' section.  I realise from my other reading in 'the conversation' that's it's not about the how-to. What I took away from the book, and I hope this was the point you were trying to get across, is that it's not about the beliefs that I hold about myself (I), but that the 'I' itself is just a set of beliefs. Correct?  So the questions that spring to mind are, 1. how did they get there? and 2. what keeps them in place? Did I miss that in the book? Does it even matter?