From M. John Harrison:
Over-sophisticated notes tend to retain their strong original structures, along with attachment points which permit them to be bolted on to one another only at certain angles. They become little bits of fiction in themselves. Much of the effort of writing then consists not just in breaking up these structures–seeing them in a new light–but in knocking off shaping conventions & writing new ones in an effort to encourage connectivity. If, despite this juggling & bridging & gentle provision of opportunity, the components still won’t fall into the shape they seem to suggest, then some grosser intervention has to be provided. One’s reluctance to resort to this isn’t just a reluctance to be untrue to the perception contained in the original material: it’s the terror of the false note. Or, really, the terror of the search to find the true one.
This may be a prolegomenon to a theory of the efficacy of shitty first drafts — if too much of what you wrote is good, the bad parts of the structure inherit resistance to editing from the good, and the whole thing rejects improvement (absent “grosser intervention”).
This is especially true for the “attachment points.” You can get into situations where the work effectively flits in and out of parallel universes — parts of the narrative depend on something having happened or being known to someone, parts depend on the same thing not having happened or being unknown. Collapsing the quantum superposition of these possibilities inevitably occasions a massacre of darlings, to say nothing of the sheer vigilance required in making things make sense again.