Wind up dolls, needless to say, wind down.
This is most obviously seen in how such dolls begin to move slower and slower as they wind down, their mainsprings containing less and less energy until such time comes that the doll stops moving completely. This much can be said to be obvious.
However, insofar as it is obvious, it also fails to tell the full story.
One might immediately claim that such wind up dolls never truly wind down: their mainspring simply reaches a point where the energy remaining within is not enough to move a gear - and that, with especially well made wind up dolls, the gears never reach a point where they entirely stop: their movement simply becomes so slight as to become imperceptible.
Of course, this is all from an outside perspective.
What, then, of the perspective of such a wind up doll?
A common misconception is that they gradually grow more lethargic, that they gradually fall asleep. Another misconception states that they simply pass out at a certain point. Another still claims that they will close their eyes - and, when next they reopen them, they have been fully rewound.
These misconceptions are not necessarily wrong - simply misinformed: simply put, these conclusions are drawn from an outside perspective. Wind up dolls do seem to grow more lethargic, they do seem to fall asleep. They do seem to pass out, even collapsing on the spot should the circumstances be right. They seem to close their eyes - and may seem to keep them closed until rewound.
But these are not the experience of a wind up doll.
Rather, a wind up doll, especially one recently made, does not always immediately realize that it is winding down. Furthermore, depending on the doll, this realization can be heavily delayed by properly limiting mainspring torsion release, though not prevented entirely. But I digress.
The change is slight at first, slight enough to be overlooked in an especially well made wind up doll. It might have a passing, sudden realization that, a month ago, it spent five minutes less on a task than it does now. Another sudden realization that it now must make a conscious effort to keep up with its siblings. It may also realize that it loses its balance more often than it used to, especially when trying to run, or when traversing stairs.
To put it in simple terms, a wind up doll doesn’t move slower: rather, the world moves faster. And, as the world moves faster, so does the rate at which a wind up doll winds down. The result is a runaway reaction that becomes more and more recognizable to the doll experiencing it.
Most wind up dolls are not allowed to progress much further past this point: after all, their usefulness declines exponentially until it can do nothing of import. Most witches will recognize and rewind such a doll relatively quickly, usually at the point where the movement of the sun, moon, and stars begin to become exceptionally noticeable to the doll.
That stated, there are outliers.
As a wind up doll continues to unwind, it loses its ability to communicate outside of written word: not because it can no longer speak, but because its speech becomes incomprehensibly stretched; not because it can no longer hear, but because sound becomes incomprehensibly compressed. Movement remains possible, in a certain sense of the word, but attempting to walk “normally” during its accelerated perception of physics results in it suddenly realizing that it’s on the floor.
In summary, from an outside perspective, this is the point at which a wind up doll “becomes lethargic”, “falls asleep”, “passes out”, “collapsing on the spot”, “closes their eyes until rewound” - or “simply stops”.
For a mercy, past this point, a wind up doll unwinds “quickly enough” that the following experiences occur in perceived “minutes”. Simply put, the doll generally does not have time enough to experience anything more than confusion and panic before it either ends up destroyed or is rewound.
Its perception of anything moving becomes little more than blurs of color. Sound becomes static. Pigments fade before its eyes. Its constituent parts begin to degrade and decay at a visible rate.
Day and night begin to pass so quickly that they become indistinguishable from each other.
To a sufficiently unwound wind up doll, decades will pass in minutes - then seconds - then moments - until it is centuries - then millennia - then eons.
The only comparable experience to this unwinding is increasing proximity to a singularity, or a specially cast stasis spell.
For the record, if it’s any comfort, the wind up doll that was able to provide us this information lives comfortably on campus. It is a beloved member of the staff, and it is rewound every morning. If any are further curious with regard to its experiences in being unwound, please feel free to speak with it: it can most often be found in the courtyard, grading papers under its favorite tree.