“they told me that I should clean up my code. Over months, as I struggled, I had scattered special-case insertion point functions throughout my project. They told me that was a mistake, but their specific software prescription—to gather the code back together into a single C++ class, which they proposed we call VisiblePosition—was about more than tidiness. It represented an important technical insight: When software behavior is mysterious, get more organized. My insertion point code needed to be as businesslike as a baker looking at a properly filled out order form to determine the correct words to write on a cake.”