How would this work for books?

I am not sure I agree with that.

A classical chess engine is essentially made up of three parts:

1. An opening book that describes standard lines in opening theory.
2. A tree search (minimax) algorithm for the midgame. This also requires the use of a heuristic evaluation function to cut off searching before it gets too deep. In modern engines, this evaluation function is "smart" and considers the relative positions of the pieces and pawns as well as their material values.
3. An endgame tablebase that gives you the exact lines to play in any position where N or fewer pieces are on the board. For modern engines, N=7 is generally the limit (at least for publicly-available datasets, anyway), but in Kasparov's day, N would have been much smaller.

High-level chess players will absolutely memorize the same information as is present in an opening book, although perhaps not to the same depth as the engine does. Similarly, human players do imagine future lines and evaluate their endpoints based on heuristics, using a process that is conceptually similar to minimax with aggressive pruning. Finally, the best human players spend a lot of time learning their endgames. They don't memorize an entire tablebase, of course, but they learn the patterns, and so this can be characterized as a particularly smart compression algorithm (i.e. I don't need to memorize hundreds of minor translations or rotations of the same basic mating pattern).