It's a good moment for the adage "oppose book worship", I think:

Whatever is written in a book is right — such is still the mentality of culturally backward Chinese peasants. Strangely enough, within the Communist Party there are also people who always say in a discussion, "Show me where it's written in the book." When we say that a directive of a higher organ of leadership is correct, that is not just because it comes from "a higher organ of leadership" but because its contents conform with both the objective and subjective circumstances of the struggle and meet its requirements. It is quite wrong to take a formalistic attitude and blindly carry out directives without discussing and examining them in the light of actual conditions simply because they come from a higher organ. It is the mischief done by this formalism which explains why the line and tactics of the Party do not take deeper root among the masses. To carry out a directive of a higher organ blindly, and seemingly without any disagreement, is not really to carry it out but is the most artful way of opposing or sabotaging it.

The method of studying the social sciences exclusively from the book is likewise extremely dangerous and may even lead one onto the road of counter-revolution. Clear proof of this is provided by the fact that whole batches of Chinese Communists who confined themselves to books in their study of the social sciences have turned into counter-revolutionaries. When we say Marxism is correct, it is certainly not because Marx was a "prophet" but because his theory has been proved correct in our practice and in our struggle. We need Marxism in our struggle. In our acceptance of his theory no such formalisation of mystical notion as that of "prophecy" ever enters our minds. Many who have read Marxist books have become renegades from the revolution, whereas illiterate workers often grasp Marxism very well. Of course we should study Marxist books, but this study must be integrated with our country's actual conditions. We need books, but we must overcome book worship, which is divorced from the actual situation.

How can we overcome book worship? The only way is to investigate the actual situation.

And:

V. THE AIM OF SOCIAL AND ECONOMIC INVESTIGATION IS TO ARRIVE AT A CORRECT APPRAISAL OF CLASS FORCES AND THEN TO FORMULATE CORRECT TACTICS FOR THE STRUGGLE

This is our answer to the question: Why do we have to investigate social and economic conditions? Accordingly, the object of our investigation is all the social classes and not fragmentary social phenomena. Of late, the comrades in the Fourth Army of the Red Army have generally given attention to the work of investigation, [3] but the method many of them employ is wrong. The results of their investigation are therefore as trivial as a grocer's accounts, or resemble the many strange tales a country bumpkin hears when he comes to town, or are like a distant view of a populous city from a mountain top. This kind of investigation is of little use and cannot achieve our main purpose. Our main purpose is to learn the political and economic situation of the various social classes. The outcome of our investigation should be a picture of the present situation of each class and the ups and downs of its development. For example, when we investigate the composition of the peasantry, not only must we know the number of owner-peasants, semi-owner peasants and tenant-peasants, who are differentiated according to tenancy relationships, but more especially we must know the number of rich peasants, middle peasants and poor peasants, who are differentiated according to class or stratum. When we investigate the composition of the merchants, not only must we know the number in each trade, such as grain, clothing, medicinal herbs, etc., but more especially we must know the number of small merchants, middle merchants and big merchants. We should investigate not only the state of each trade, but more especially the class relations within it. We should investigate the relationships not only between the different trades but more especially between the different classes. Our chief method of investigation must be to dissect the different social classes, the ultimate purpose being to understand their interrelations, to arrive at a correct appraisal of class forces and then to formulate the correct tactics for the struggle, defining which classes constitute the main force in the revolutionary struggle, which classes are to be won over as allies and which classes are to be overthrown. This is our sole purpose.

What are the social classes requiring investigation?

They are:

The industrial proletariat The handicraft workers The farm labourers The poor peasants The urban poor The lumpen-Proletariat The master handicraftsmen The small merchants The middle peasants The rich peasants The landlords The commercial bourgeoisie The industrial bourgeoisie

In our investigation we should give attention to the state of all these classes or strata. Only the industrial proletariat and industrial bourgeoisie are absent in the areas where we are now working, and we constantly come across all the others. Our tactics of struggle are tactics in relation to all these classes and strata.

Another serious shortcoming in our past investigations has been the undue stress on the countryside to the neglect of the towns, so that many comrades have always been vague about our tactics towards the urban poor and the commercial bourgeoisie. The development of the struggle has enabled us to leave the mountains for the plains.[4] We have descended physically, but we are still up in the mountains mentally. We must understand the towns as well as the countryside, or we shall be unable to meet the needs of the revolutionary struggle.

https://www.marxists.org/reference/archive/mao/selected-works/volume-6/mswv6_11.htm

Mao was encouraging revolutionaries to be this meticulous about class observations and noting down the particulars of them in a given region. Then in this thread, we're arguing over out of context book quotes on the internet - quotes that exaggerate and oversimplify.

I get tired of it in the context of discussion about the US because it is often spoken of in lockstep with a fatalistic attitude about the revolutionary potential of the people there, rather than as a means of better understanding the class makeup of the region in detail, in order to contend with it. It also risks being used as a form of blame-shifting; "we failed because they actually were too comfy as they are and didn't want to be liberated." Meanwhile, Mao is like "here's one of our shortcomings in how we're going about engaging with people who live a different kind of life than what we're used to."