Memory has no changelog

We asked two route planners to write down how they route fibre and got back 98 sections — which turned out to describe routing by who owns the building, while the same engineers had for years actually been routing by what’s physically installed there. This is how we stopped asking people to remember, recovered the real rules by replaying historical decisions out of the inventory database, why the target turned out to be agreement rather than correctness, and the one line of code I invented by accident that got one in four trunk selections wrong without ever raising an error.