I just wanted to share this with you:

https://blog.udemy.com/object-oriented-programming-a-critical-approach/

As mentioned in the post, I also believe that a lot of the beauty of OOP as defined by smalltalk has been lost.

So, if you have not learned smalltalk, you should. It’ll change the way you think about OOP.

Here’s something to help you get started:
http://rmod-pharo-mooc.lille.inria.fr/MOOC/WebPortal/co/content.html

enjoy!