Most writers know roughly what they mean in their first draft, and in the process of revising and re-drafting they try to get closer to that known meaning.
But what is natural and spontaneous in history seems to be almost the reverse of this.
Original intention counts for very little, the specifics (an image, a turn of phrase) of an incident stay the same; but the interpretation of the incident may be radically altered or even reversed.
This pattern is often seen through traditional oral transmission of narratives, it is seen in the mass media, and happens in many movies that adapt books - the specifics may be retained but their meaning transformed.
I have seen this happen with a couple of maxims during my life.
When I was a child the story of King Midas - everything he touched turned to gold - was regarded as a cautionary tale of greed leading to (potential) death (since his food and drink were also turned to gold).
But nowadays, 'The Midas Touch' is regarded as something desirable - it means the ability to make money in any situation.
So a successful entrepreneur is described as having the Midas Touch, like it was a good thing to have.
(Presumably for modern people the benefits of wealth are now regarded as greater than survival!)
"Shooting yourself in the foot" used to mean a deliberate act of relatively-minor self-wounding, with the aim of being invalided away from the front line of a war.
Someone shot themselves in the foot on purpose, but pretended it was an accident.
But it now the expression means almost the reverse - having shot oneself in the foot is used to mean an having accidentally self-inflicted harm - rather as British people use the expression 'scoring an own goal' - referring to a situation in which a Soccer defender perhaps tries to pass back to the keeper, or kick the ball into touch - but accidentally scores a goal against his own team. Or - for US readers - the baseball-derived equivalent term might be an 'unforced error' - used generally to mean a gratuitous piece of incompetence.
So a corporation which launches a new brand which collapses and damages the company is nowadays sometimes described as 'shooting itself in the foot', since the company was harmed by a action which the company itself initiated - despite that the harm was accidental.
In both Midas and Shooting in the Foot, a striking detail is preserved, but its meaning is transformed.
And this seems to be quite normal for human memory: we remember striking things in a photographic (eidetic) fashion, as static and detached units; but we do not remember what they mean.
The contextual meaning of a unitary and static memory has to be supplied by our current selves, and the context often changes.