The premise is the introduction is wrong. "so before we have written a single program in our language, before we know whether shared behaviour will be importan

The premise is the introduction is wrong. "so before we have written a single program in our language, before we know whether shared behaviour will be important in the applications that will be written in it" read the POODR book, or watch this https://youtu.be/OMPfEXIlTVE?list=PL5s3t9kPeAN6aDxaSywIbeFJOCfm7ixpi https://youtu.be/OMPfEXIlTVE?list=PL5s3t9kPeAN6aDxaSywIbeFJO... it explains how shared behavior works without code duplication and why people tend to mess it up.