Yeah, it took a bit for me to find the right metaphor. I started with a pyramid but really your mind isn't built like that. I do think it's helpful to just be able to visualize why some ideas are harder to change than others and how what you "know" is build upon and shaped by individual blocks of knowledge.
A site I mentioned in another post was allsides.com. It a good way to quickly see all the angles on a story.