no graph means you don't know how to fish.  it's the fishing line and tackle.  unless you're enough of a math wiz to have a graphing calculator or see how a node works in your head.  if you're as bad at math as everyone says they are, you cannot understand what's going on in any shader with most math nodes or anything variable without a visual of what it's doing.  no matter how it's presented.  there simply is no english that better describes a power curve than actually seeing it.

"You always have folks who can't understand something as it's explained by the current curriculum." look at the forums.  the current curriculum, other than some of bagginsbill's posts, is ignore the math and just plug stuff in randomly and see what gives the right result in certain lighting.  we already have what people are asking for here.  go thorugh Acadia's thread.