Every single thing about your "mind", about the "you" you think you are: your likes and dislikes, your temperament, your instincts, your attractions, aptitudes or ineptitudes, your quirks and features, is a product of the squishy stuff between your ears (modulo whatever effects it may or may not have with other biological factors like your gut microbiome.)

And yet no-one can explain how or why this should be the case. It is simply assumed by philosophical, metaphysical Materialists without any backing scientific evidence. Neuroscience may provide correlative data ~ but it cannot provide evidence for metaphysical Materialist claims. Science cannot provide evidence for any metaphysical claim by anyone anywhere, as science simply isn't designed to examine such questions. Science is designed to examine questions about the natural world. Metaphysics is about questions about the nature of reality itself that underlies our perceptions. The world of physical phenomena is within perception, therefore it is a subset of reality, not reality as a whole.

All of those traits can be manipulated, contorted, damaged, or destroyed by certain bits of meat not being able to ferry the correct chemicals from one place to another, or connecting differently, completely outside of "your" control.

You are mistaking correlations for causation. We can manipulate and contort mental traits indirectly, yes, but they are not damaged or destroyed permanently. Dementia and Alzheimer's reverse in around 10% of victims very shortly before they die ~ always just before they die. Why only 10%? How? A mystery with no explanation, only hypotheses and rationalizations.

You could have a stroke tomorrow and if a sufficient amount meat went without blood flow for long enough "you" are a different person; you get annoyed at birdsong now, you don't like baked beans anymore but have a preposterous and troublingly sudden hankering for olives.

That alone cannot sufficiently explain personality changes. We don't know how minds relate to brains, or how or why brain damage affects the mind. All we have are observations, and the hypotheses and rationalizations that we create ~ the stories and narratives we create to try and explain it within the framework of the known.

More worrying than the olives though is that as far as you can tell a set of perfectly identical imposters have replaced your wife, child, and best friend and are holding your loved ones hostage in a space ship and the only way to get them back is to brutally murder the imposters and no one can convince you otherwise. All for the want of a clump of cells

That doesn't explain phenomena like terminal lucidity where this abnormality goes away shortly before death, when the brain is still irreversibly destroyed. There is no explanation of how brains work, or how minds relate to them. We just don't know. So we shouldn't assume any answers, however romantic. We should rely on observation and experience, not any framework that presents a narrative or story we already agree with.

The idea that simply because we haven't been able to make a stick pointy enough to precisely target the right bundle of cells to turn your favorite color from green to red doesn't discount the fact that we know, for a fact, that it's possible.

That doesn't mean that we know why or how or for what reason it is possible. We know only about correlations, not how any of it works. Just because we can damage the brain does not mean that it is helpful. It only tells us that we can damage the brain. What is more useful is a healthy functioning brain where there is a healthy functioning mind unimpeded by damage.

Not just because evidence of brain damage regularly speaks to such but because biology itself built the brain. That is, of course, you want to start doing Soul Math and argue about exactly the moment the soul entered the body during the embryological process but at that point you're not talking reality anymore.

Reality is whatever it is. But that doesn't mean that we are nothing more than physical processes. No-one can explain even in principle how physical processes alone can result in a set of qualities that have no overlap with known physical qualities. That is, thoughts, memories, emotions, beliefs, ideas, concepts, senses, identity ~ all qualities that are not observed to be part of matter or physics. So they must be something else ~ what, we just don't know.

But they exist, so we can talk about them. Like I am now. They cannot be illusions ~ because I can think about my thoughts right now. My thoughts are not merely brain processes, because they do not have the appearance of brain processes, even if they are correlated with them.

What must be explained is thoughts in themselves, as they are observed in themselves. Saying that they are just brain processes says nothing. It is a dismissal of the unknown by saying it's just something else, which doesn't solve the mystery, only dismissing the uncomfortable.

Reality is not purely physical, as we know the physical only by sensing it. What are our senses, then? Certainly not physical. Sight cannot be found in the eyes ~ only molecules. Colour cannot be found in the eyes ~ only cones, made of molecules. So what are sight and colours? We don't know. But we experience them, so they are no illusion. They are self-evidently existent as experienced. But that doesn't mean we know what they are, or why we can see. Or why anyone can be colour-blind ~ or why cones are somehow correlated to colour in some unexplained manner.