The Role of Material Design in the Design of Google Apps

I love how you described your process of actually inventing apps or making fake apps to test your hypothesis about what would work in different situations. But material design has also gone as far as to prescribe color, palette and fonts, type of process. Why did you go that far? And are those even rules? And is that the purpose to make it even more consistent? Those are actually not rules at all. I mean, they're, I'll say they're rules for the way that most Google apps will behave.