tl;dr:The post emphasizes the importance of "code locality" in programming, arguing that readability is not merely subjective but is constrained by human limitations such as short-term memory and screen size. The author outlines principles derived from the concept of code locality, including maintaining high cohesion and low coupling, writing less code, avoiding repetition and global variables, preferring composition over inheritance, defining variables close to use, conserving vertical space, and considering inlining variables and functions used only once. Code locality, by aligning with human cognitive constraints, is a fundamental criterion for effective programming.