This may be a fallacy. It is all connected. Some of the connections are not obvious at first. It's very tempting to create interesting features for your own edification or satisfaction, and leave them nearly undocumented. Years later, kind-hearted strangers discover these in the code and wonder why no one knows about them. Sometimes, it's like code that you just wrote for yourself might as well not even exist for the rest of the world. That's just one facet of this situation.