In English class we were encouraged to write drafts and make edits until our words were as clear as filtered water. In math we were warned to review our workings, ensure the figure at the end was correct. And in music we rehearsed songs a hundred times, trying out a glut of harmonies before Mr Hunt was satisfied. Yet when it matters, when it's a life-and-death decision, like whether to slice ourselves apart or not, we've no way to perfect the path we're taking and have only one choice and one chance to get it right.