> Knowing when two things are one thing or one thing is two things is most of our job, right? Yes, but often we don't know the domain enough but "this feature

> Knowing when two things are one thing or one thing is two things is most of our job, right? Yes, but often we don't know the domain enough but "this feature must be available yesterday". So add tests, copy, release. And when you have to either do it again or have to update this code and its original you should know more and be able to refactor and give good names to everything.