One distinct memory stands out. I could not wrap my mind around the Object-Oriented extensions on Pascal. I read, re-read, and re-re-read the section of the book describing what polymorhpism is and how it worked, probably at least a dozen times. Somehow it seemed really important and I kept coming back to it. I worked the examples. And then one day the ah-hah moment arrived. I remember it felt like a shock, why it was useful and what I could do with it. I promptly used my knowledge to write a new game using OOP principles to guide the rudimentary "characters" of various geometric shapes at the core of the game.

Fun times, and very formative to me!