Here is the Big Assumption: There are only so many things objects can do. Not in the sense that there are a limited number of applications, because there will always be new domains to model, but in the sense that the same structures of objects keep appearing over and over, regardless of the application. The problems in the construction of objects are universal. You have to name classes, relate classes via inheritance and delegation, relate methods in the same class and different classes, name variables, and so on. Patterns record these problems and how to approach solving them.
***, what patterns do?
