Chalk that up to the age of the stuff that I've been reading recently (LISP 1 and LISP 1.5 manuals).

Yeah, the dinosaurs were still alive, then.

I figured 'go to the source' is the best way to really understand what's going on, and it's been quite the eye opener to see 'simple' lisp next to all the superstructure that has been placed on top of it since then.

I'm not sure if I should recommend anybody to go the same route (since I'm still very much a FP/Lisp newbie, so my words carry little to no weight at all) but it worked well enough for me that stuff made more sense after doing that.

Sure, it makes sense if you are interested in that stuff. There is a wealth of material. More than a person can read in a lifetime. But it may be more important to hack the new stuff, otherwise you get sucked into that Lisp thing. Like me.

I actually have the blue book open in my pdf viewer right now. I jumped back into it after I re-read Gabriel's Design of Parallel Languages few days ago.