Courage

Test-driven development is a way of managing fear during programming. I don't mean fear in a bad way—pow widdle prwogwammew needs a pacifiew—but fear in the legitimate, this-is-a-hard-problem-and-I-can't-see-the-end-from-the-beginning sense. If pain is nature's way of saying "Stop!" then fear is nature's way of saying "Be careful." Being careful is good, but fear has a host of other effects.

Fear makes you tentative.

Fear makes you want to communicate less.