While using Unreal Engine, I always had a vague curiosity about how its features work internally and why they were designed with such structures. Most available courses focus heavily on how to use the engine interface, which left me feeling unsatisfied, but I feel like I've finally found a truly great course. The most satisfying part was being able to implement the engine's fundamental mechanisms with my own hands. Beyond simply creating features, designing the Actor lifecycle and Tick system myself allowed me to think deeply about what an object-oriented code structure really is. Thanks to this, I feel like my code—which used to be messy because I was only focused on implementation—is gradually finding order. In particular, the part where we implemented custom RTTI and managed memory was impressive. Instead of just using the features provided by the engine, learning the principles of managing runtime type information and casting safely gave me a lot of confidence in C++ and memory structures. The process of separating the engine into a DLL and linking it was also fresh; it was practical knowledge that is hard to find in typical tutorials, and it was a great help to my CS studies. After completing the course, every class name and variable in Unreal Engine looks completely different to me than before. I highly recommend this course to those who want to properly understand the massive structure of the engine or those who want to grow into developers with real skills. I would like to express my sincere gratitude to the instructor for being such a great guide.