One thing to consider is that your code will be hard to maintain by others if you can’t at least communicate your big picture. And ideally, everything should be subdivided into modules with clearly defined interfaces, so that each module can be independently reasoned about based on (only) its interface definition. This increases maintainability because things can be reasoned about locally. People also differ in how much detailed context they can hold in their head at any given time, so the smaller the required context can be made for reasoning about any given piece of code or part of the design, the better.