 fMRI show that we receive some of our highest dopamine doses during the discovery phase of learning. The exact aha moment has a chemical analog. You get surprised, you get a little jolt to your learning center so you'll remember what surprised you. So to simplify, we like learning, we like surprises, and we really like learning that surprises us. Discovery, discovery, in dealing with the problem, you very often come upon outcomes, images, or ideas that emerge that were not anticipated at the outset, but nevertheless are filled with promise. And so you pursue the promise. You pursue the surprise.