The discussion centers on the perceived difficulty of various branches of physics, particularly after experiences with Newtonian mechanics. Participants emphasize that difficulty is subjective and varies based on individual backgrounds in physics and mathematics. A solid foundation in introductory physics and calculus is deemed crucial for tackling more advanced topics. While some believe that areas like quantum gravity and condensed matter physics are among the hardest, others argue that many undergraduate and graduate topics, such as classical mechanics and electrodynamics, may seem easier with proper preparation. The conversation highlights the importance of personal experience and the varying levels of challenge different individuals face in their physics studies.