The short answers are “complexity” and “targeting” essentially. How do you stimulate or inhibit what you want to target and only what you target, especially whe

The short answers are “complexity” and “targeting” essentially. How do you stimulate or inhibit what you want to target and only what you target, especially when as you point out we’re bags of mostly water? Looking at something like stimulating a specific region of the brain, how do you keep yourself from imaverdently stimulating neighboring neurons? Not only that, but far more isn’t understood about the exact functioning of the brain than what is known. Barring luck, it seems reasonable to expect that comprehension of the system needs to precede fine control over it.