Some of my most productive days ever lacked sleep, healthy food, or exercise, but kept me going with the excitement of a new idea or approaching milestone.
Mood as Extrapolation Engine: Using Emotions to Generate Momentum
Tiago Forte

I’ve had so many days like this. It’s also always fascinated me how long, highly-productive days simply feel shorter/quicker than actual shorter days which drag on without productivity — as if there’s some tangible temporal relationship with productivity. Time flies when you’re having fun! =)