Jiang Yuan worked the whole day.
Those familiar with three-dimensional modeling know that once the functions and formulas are set, the work speeds up, especially when you're familiar with what each variable represents. As long as you have the mental stamina, sustained work over a long period doubles and redoubles efficiency.
But once interrupted, to get back into the previous flow might require another hour or two of immersive work.
This is also why many who work in mathematics, physics, and computer programming often have poor digestion. When it's time to eat, if work is going smoothly, they simply can't bear to step away; and when it's not, they still can't leave because they have to make up for lost time.
