The same four-line pattern appeared in five places. I tried extracting it as a function. Every version of the signature either papered over a real difference or forced three of the five callers through an awkward conversion. I tried a second shape, then a third. Each felt wrong in a different way — either the abstraction was too thin to be worth it, or it obscured something the original made obvious, or it made the rare case ugly. I went back to the original code, considered not doing the refactor at all. Considered it. Went back to the shapes again. The pattern was clearly there and I clearly wasn't finding its seam.
