The eternal struggle of physicists - can't even ride public transit without mentally solving differential equations! That poor subway rider is witnessing the classic "physicist in the wild" phenomenon. While normal humans think about dinner plans, our physics friend is probably calculating Kerr metric properties (you know, just the spacetime geometry around rotating black holes, casual commute thoughts). The fascination with someone doing complex calculations in public is peak nerd-spotting behavior. Next time you see someone staring into space on the subway, they might just be revolutionizing our understanding of the universe... or deciding what to order for lunch.