Writing good, maintainable code and tests requires removing yourself from the immediate concern of instructing the computer to do something and instead concentrate on explaining the desired behavior to another human being. That human could be a team member who never interacted with the code before, your pair while you are writing the code, or yourself months or days later. Using System Metaphor and BDD (aka TDD done right) highlights the story telling that is intrinsic in this way of developing. We will cover some examples of how to apply this and what you might find happens as a result. Examples will come from work on a new component of the open source puppet server automation tool.