I find it utterly strange that drugs, hallucinogens, concussions, alcohol, electromagnetic stimulation, etc. could all reliably affect consciousness but that a

I find it utterly strange that drugs, hallucinogens, concussions, alcohol, electromagnetic stimulation, etc. could all reliably affect consciousness but that a brain identical to mine might be a pzombie. Like; who or what could possibly be doing the detailed-enough tracking to be sure to give my brain consciousness (but not my sleeping brain) while my molecular twin gets none?