Fair enough. But most of the forming is by doing. Someone gave an analogy to music. You can't become a great musician by reading books. Some great musicians have never read a book about music. But yes, reading can be (a great!) part of the learning process. My point was more about rules. The article says things like replacing complex conditionals with intermediate variables. The idea that a certain construct always have higher cognitive load and should be replaced with another is too simplistic IMO.
In order to get a sense of what code is harder to understand you will do better to read code and have others read your code. A good takeaway is to keep this in mind (amongst many other factors) and to understand code needs to be maintained, extended, adapted etc.
The ideas are still useful. The danger is blindly applying rules. As long as the reader knows not to apply any of the suggestions if they don't understand why and have relevant experience ;)