It’s the social environment and performance, often sustained for hours, that’s entirely unlike anything else I do. It’s not like emergencies (great at those), it’s not like being in a meeting with a hostile client (good at that), it’s not like any socially-difficult thing I do in work or life outside of it, and it’s certainly not like normal collaboration. Programming while being watched and judged is horrible and energy-sapping in its own special way.