I'll try to make this as clear as possible. Does it make more sense to assume that consciousness within the individual is a singularity, so that we each have just one, or can each separate experience be regarded as a separate consciousness within the same brain becoming one with the others only through shared memory and personality programmed into the brain itself?

In theory, could you ever hook up the right half of the brain of one individual with the left half of another individual, so that all memories, thoughts, decisions and feelings are now shared between the two halves in the same way they are between the halves of the regular human brain? It seems like if this ever happened it would result in these former individuals no longer being able to think or experience the world independently, and certainly this newly formed brain would have internal dilemmas, but in the same way regular humans do within their own minds, with one idea eventually overshadowing the other. If two minds can theoretically become one only through the power of nerve circuitry then it seems like that's all that's keeping our own unique experiences from becoming subjective experiences in their own right within a single brain, so that they may be understood as one coherent experience instead.