The class seemed to have just begun.
Lu Zhou gently pushed open the back door and looked at the middle-aged professor facing the class. Lu Zhou didn't interrupt the students who were listening to the lecture, nor did he interrupt the students with their heads on their desks. He found a low-key spot and sat down.
Inspiration didn't just come by itself, he had to go search for it.
A quote by Fermi resonated with Lu Zhou, which was that thinking about easy problems would depend on one's understanding of esoteric problems.
This seemed to apply to both mathematics and physics.
When Lu Zhou was in Princeton, whenever he encountered a problem he couldn't understand, he would take time to lecture some undergraduate students, or he would go to other professors' classrooms to find inspiration.