Whenever I read about new renderers I think I'm completely intellectually inept even with what I think is a reasonably well-rounded computer science education. It is like reading about string theory in a way. Sure, I can grasp the concepts, but the details and minutia are fascinating and admittedly a little beyond my immediate comprehension. I remember when POV-RAY was amazing when it ran all night to produce just one image with some reflection on a 486.
I suggest taking a look at Physically Based Rendering [1]. It goes through an advanced rendering system in a literate coding style. That is, the physical explanations are interspersed with the code of an open source renderer [2]. I'm not sure how it compares with this Disney renderer, but it should go a long way towards demystifying how these things work.
I wouldn't worry about it too much, Computer Science is past the point where you can have intricate knowledge of all of it. Knowledge of the existence of most things is good enough imo.
Also it goes both ways, I doubt the people writing these renderers have intricate knowledge of modern networking or web stacks etc.
How time and Moore's law flies...