There's one source of bugs that the author doesn't mention: time, and how our understanding shifts with it. Sometimes the understanding of what a business obje

There's one source of bugs that the author doesn't mention: time, and how our understanding shifts with it. Sometimes the understanding of what a business object (or one of its attributes) represents sometimes shifts, over the course of several years. Sometimes, that shift is suble and easy to miss, like that it used to represent a desired state, and now more often represents an observed state. Sometimes, other ways to manage some objects come about, and of the original use cases of an object or table, only some (formerly niche) use case remains. Sometimes our use of language drifts, for example when a third-party tool is introduced that uses similar but not-quite-identical vocabulary. All of these can lead to formerly correct behavior now being obviously wrong. Sometimes it's hard to remember the context of the original implementation, and you ask yourself why anybody in their right mind would have done what you did back then.