We all know these stories about people working 10, 12, 14, 16 hours per day for weeks or months. I personally don't understand how something like this is humanly possible. What is the mindset behind this? How are these people able to work that much without exploding? Most of the work that I do is programming which is incredibly cognitively demanding. After 25 - 30 hours, I already feel tired. I pushed it sometimes in the past, however after 40 hours, it becomes too much for me.