As a young software engineering student, I spent an inordinate amount of time reading about OOP. I was trying to understand how OOP works and why it's so important for modern software development. At that time, most books were mentioning that OOP is about organizing code into classes that have three important properties—encapsulation, inheritance, and polymorphism.
Almost 20 years later, I realized that this vision of OOP was quite limited. OOP was largely developed at Xerox PARC, the laboratory known for generating an amazing number of high-quality ideas, such as graphical user interfaces, point and click, the mouse, and the spreadsheet, to mention just a few. Alan Kay, one of the OOP originators, drew from his knowledge as a biology major while facing the problem of organizing large code bases in ways that supported the new GUI paradigm...