But it would help the OP better formulate his question. He's thinking he needs to internalize Bayes theorem, when in fact what is really important is that he needs to understand probability theory, of which Bayes theorem is one manifestation. Note that Bayesianism describes a philosophical movement, not scientific or mathematical. You don't find statisticians discussing probability theory along such tribal lines. So asking tribalistic questions is perhaps not the best strategy to tease out understanding of the underlying model.
On LessWrong, Bayesianism is probability theory. Moreover, it is bundled in with subjectivism about probability, determinism, many worlds theory etc. It all comes down .to whether the OP wants to become a rationalist, or a LessWrong rationalist, like deciding whether you want to be an economist or an Austrian school economist. If the former, some unlearning will be required.
The current state of my understanding (briefly):