Renormalization Group (RG) is an advanced mental model that attempts to explain why scientific theories are often so effective, even when it is practically impossible to precisely determine all the parameters. For instance, a human being is fundamentally a complex assemblage of interacting subatomic particles, but we are able to easily recognize humans from other species because we can  broadly identify their key physical and behavioral characteristics, without comprehending their electron configurations. Such abstractions allow us to understand our macro world, but a key question that must be asked is: “why can we do that?”