When I only watched other instructors' free Java YouTube lectures, I didn't understand polymorphism. On the other hand, instructor Kim Young-han explained what kind of inconvenience each concept was needed to solve, which was really great. Even before learning the concepts, I thought, "I wish I had this function," and I was surprised that I had the experience of putting it into practice later. I hope the intermediate and advanced lectures come out soon. I really recommend it!! +) Cow is Cow in English 🤣