I'm having an incredibly difficult time following this. I've understood- or at least thought I understood most of the sequence thus far, but this post in particular is really rough.

Perhaps that is just a matter of having substantial amounts of actual math in front of me where I expect lesswrong posts to be shiny and easy to digest? To become stronger one must challenge oneself, and most of the posts on this site go down smooth.

That is a trade off of making a subject more approachable: when it becomes less shiny it is much harder to retain interest. Lesswrong is very, very shiny indeed. Then again I probably wouldn't have had such interest in quantum mechanics otherwise, so maybe this is simply where the rubber really hits the road.