How is it that sometimes you read something and you totally get it? While other times you have to read something 20 times in order to remember it?
The answer is context-based learning vs insight based learning.
Today in society we primarily focus on one version of learning which is context-based learning. This is reading information and actions and then practicing these actions or repeating the information over and over again until you remember to do it.
In society and even in religion we have forgotten that there is another way of learning. This way of learning is called insight based learning. We are reading information which has power and meaning behind it.
The information is not telling us to do anything, however, after reading the information we might just get an insight and completely understand what that information means to us.
Of course, context-based learning is not a bad thing.
If we put it in the context of magic, we are reading and studying routines, meaning that we have to learn and practice these routines in order to perform them. (Context-based learning). Although, maybe sometimes you are just reading a routine and a new insight pops up.
Context-based learning is very good as well, however, if we look at performing magic it might be a problem. Books telling you to do this or do that can be problematic. The actions that the person is recommending you might not be natural to you, they might feel weird or even unpleasant to other people.
Reading a book that makes you understand the theory of performance, stagecraft, and magic could be a great book if it contains truth. This book is more likely to explain to you how it works and leaves it you to figure out how to apply this information to your performance.