A further harm in the analogies is that it gives a sense that my experience of self is fundamentally nothing; a chimera, a ghost, a lie my ego insists on telling because it is undisciplined and immature.
The first point to be clear about is that the locus of self is absolutely fixed. I experience 'me' via my brian and the associated physical neurological and biological systems in my body. I will grant that perhaps there is some new frontier in fine detail related to this in the recent findings regarding bacterial and perhaps even viral 'bioms' that encompass human bodies (each person carries more cells/objects [for viruses] with 'foreign' DNA than 'self' DNA), but generally speaking my experience of 'I' is limited to the physical extent of my nervous system. And more importantly, how 'I' gets represented to my consciousness is entirely occurring in the various organs of the brain.
If this is accepted, that 'self' arises from the physical structure of the nervous system, grossly represented in the brain, then 'self' is changing only to the extent that the physical structure of the brain is changing. The physical structure of the brain is largely un-changing.
I repeat, the physical structure of the brain is largely un-changing.
Additionally, it is also important to understand that he brain is not a homogenous bowl of jello. Yes, I doubt anyone actually thinks of it this way, but compared to what it really is, I think for many it might be the "same difference."
The human brain has evolved over eons. It might be even better to say that the brain which is now human has so evolved, because the structure of the human brain has been carried forward by the species that predate humans in our evolutionary chain.
The major steps in brain structure are more layered, than homogonized. That's why I like to think of the structures of the brain as 'organs', though 'regions' is likely more correct, the exact physical boundaries being uncertain. Some specifics from the brain-organ-soup are autonomic system, brain stem, medulla, limbic, visual cortex, audio cortex, pre-frontal cortex [this list is a bit of a cock-up so here's a link to a nice Wikipedia list http://en.wikipedia.org/wiki/List_of_regions_in_the_human_brain]
So, the point becomes that a very large percent of the brain is fixed in structure. The means by which I experience sight, is essentially the same throughout my life. The means by which I hear, beat my heart, 'know' to breath, is largely fixed. Many of my base characteristics are also fixed. How I process fight or flight, how I wake up and become drowsy (e.g., the circadian rhythm). And there are structures more or less permanent that formed when I negotiated high-stress (i.e., important) events in my life. The wounds from early experience such as a fight in childhood, or significant lack of parental care. My biology, DNA inheritance, and early experience all layer in my brain, giving rise to my 'self' (see earlier posts such as "sub-conscious karmic oxen", and "to understand your mind, understand a tree").
There is also a part of my brain that is plasitc. From a high frequency plasticity which deals with ever changing sensory inputs such as sight and sound and location and position and temperature; to a lower frequency plasticity dealing with long and short term memory.
My feelings, my sense of what is going on, my suffering, is a complicated mix, I think, of my underlying fixed aspects and the more plastic aspects of my brain. It's rather like an inverse pachinko machine. An 'idea' (a neurological impulse wave from) gets launched by my sensory and other primitive reaction organs and starts its way towards consiousness. It gets pinged and bopped around by various neural connects (the pins in this pachinko machine) that are both essentially fixed (e.g., the structure of my medulla) and plastic (my cortex), until it ends up as a thought or action that I can experience consciously.
Perhaps this has been too much of a walk into minutia, so back to the point.....
Much of how I experience life is fixed. However, with practice I can exercise ways of thinking that, in a sense, either allow me to add new layers of pins in my pachinko machine, or bend the ones that are there so the same sort of situational inputs are experienced differently in my consciousness.
Some terrible childhood trauma-remembering bundle of neurons might still fire off when an analogous situation is presented to me in my adulthood, but I may be able to layer some new pins (or bend some existing ones) that divert the conscious result from panic to "okay."
It may even be possible that I can change the gross course of the panchiko balls so that sensory experience comes more directly from 'mechanical' rather than 'interpretive' parts of my brain. i.e., so that I can learn to see, hear, experience without using my judgement channels (my judgement organ pathways), but get a more direct feed from my visual or audio cortex.
There is a very large part of the self that is, indeed, permanent, and a very important aspect of the nature of experienced self is that it is also plastic. Self does change and it can be retrained. But I am here. and I am permanent. Not in the geological sense of time, but in the sense of having substance while I am. I am a pachinko machine to be reckoned with*.
[* for Chief Inspector Endeavor Morse, "I am a pachinko machine with which to be reckoned" ????]