You are absolutely correct. I really tried to follow-up in my post by adding other resources that were more about the theory and application of Object Oriented design. But unfortunately I couldn't come up with just one or two comprehensive resources. Even as I try now to list out a few that stand out for me I realize that there are simply too many, and although the Design Patterns gang of four book stands out, it is not an intro, or even a comprehensive explanation of OO. Someone newer to the concepts probably has a better recollection of the thing that really flicked the light bulb on.