The problem with our bathtub analogy so far is that it is too simplistic. We need to think about every part of the system ‘map’ as something like a bathtub of its own.
This illustration serves as a good example of complexity. How does raising or lowering the level in bathtub affect the rest of the system? Sure, you could analyze this diagram and create a mathematical equation to provide an ‘answer,’ but in the real world you can never be quite sure that you have accounted for all the possible ‘bathtubs’ out there. In the real world, different parts of the system have a tendency to interact with one another in ways no one can predict or forecast.