" One of IDEO’s designers even sketched out a “project mood chart” that predicts how people will feel at different phases of a project. It’s a U-shaped curve with a peak of positive emotion, labeled “hope,” at the beginning, and a second peak of positive emotion, labeled “confidence,” at the end. In between the two peaks is a negative emotional valley labeled “insight. "
― Chip Heath , Switch: How to Change Things When Change Is Hard