There are an infinite possible number of levels of depth of the analysis of any phenomena over time, i.e., the depth is unbounded, so there are an infinite number of possible models of the phenomena, each with its own potential narratives built by weaving the data points together in particular ways. However, in order to achieve some degree of commonly held beliefs, goals, and agreed-upon actions and rules, there must be a widely adopted model of reality as expressed in one mainstream narrative. This is particularly true of any system where decision-making that affects the whole group depends on a significant degree to the formation of a consensus, e.g., in a democracy, democratic republic, or political system that purports to be either. This implies that laws passed by such a political system will be based on consensus, which will be based on a widely adopted mainstream narrative.
Those who believe in a narrative not held by many others are sometimes subjected to ridicule as others doubt their mental stability. However, sanity and mental stability are only indirectly related to whether an individual adheres to a broadly accepted narrative. Mental stability is dependent on receiving continual and dependable rewards, positive feedback (including positive feedback from nature in finding perceptions consistent with predictions from models held), for behavior and it is quite possible for someone with a unique narrative to receive such rewards. However, adopting a non-mainstream narrative and holding somewhat or completely unique beliefs can make it more difficult to harmonize and work in conjunction with others and that can create a deficit in positive feedback, which then can lead to a loss of motivation or social confidence and, as a result, to mental instability.