One evening, after a particularly stubborn set of rotational dynamics problems, Arjun closed the laptop and walked to the window. The monsoon had paused; droplets clung to leaves like sequined memories. He thought of his father, who had learned from tattered physical copies, of friends who relied on gut feeling and intuition. The S Chand PDF had made physics systematic for him: not just a set of rules to memorize but a language to reason with. It had transformed bewilderment into method.