I thought AA's explanation of things was basically kindergarten material. Worth reading, esp if you had
the companion book, "Examples...". But the films and papers he refers to are nearly all obsolete. I gave
most of these books away long ago. The information quickly makes sense if you just practice exposure
and development of sheet film for awhile. It's harder to learn with roll film because one tends to lump
diverse lighting conditions onto the same roll. The Zone System ain't that big a deal, nor is it a religion. You take from it what is useful to you personally, just like any other exposure model. But as they say, practice makes perfect.