Regarding your fill() example, I believe his point was that uninformed decisions are a reflection of the interface exposed. Since the fill color is an implicit

Regarding your fill() example, I believe his point was that uninformed decisions are a reflection of the interface exposed. Since the fill color is an implicit global variable, and not exposed anywhere in the interface, there is no way to discover its existence or behavior except via trial and error or reading the documentation. If the fill color were either exposed via the programming interface, or were explicit, then no meta-knowledge would be required to use it. Similarly, the heap size limits in Java are global limits implicit to the system, not to the program being designed. His solution to the larger problem—data growing beyond available resources–might involve providing a better visualization of the data. Something more responsive than the feedback loop provided by heap limits. Getting an OutOfMemoryException doesn't help you to understand how the data grew beyond expectations; it is always followed by a heap dump. What if you could better understand the patterns of allocation during design instead?