OOD - Less Is More
My primary professional development language has been C++ for as long as I remember. It still is and I have no strong desire to move to something else. That also means that, many years ago, I embraced the Object Oriented Design (OOD) methodology.
I have derived Cat and Dog from Animal many times. At first, it took a while to see the object hierarchies, but it became easier. I loved object hierarchies. The deeper, the better.
Then, I started COM programming and designing using interfaces (abstract base classes) seemed to free my mind of the implementation details. I was happy. I was using interfaces for non-COM code in no time.
Then, I started using templates. First, with the help of the STL. What a concept! Later, with the help of Modern C++ Design (Andrei Alexandrescu) and the Boost libraries. Implementing design patterns using templates was amazing. Templates allowed me to do things I thought only inheritance could. I am glad I was wrong. Suddenly, my object hierarchies are not as deep.
Then, I started to learn XML and Services. Not really programming, I know, but the concept of storing all that data in a document that could be queried so easily made me question all those class getters and setters. Even some kinds of inheritance seemed overkill. Why can't classes be more behavorial and less stateful? Let XML be the state and just pass it around.
In the end, I'm still using objects. Just less of them. I guess the data is becoming more important than the code.