So I’ve got an interesting question - how does this fit with the subjective experience (insofar as we can tell) of an Alzheimer’s patient? If they can’t remember the last 20 years say, does that mean they were unconscious for those 20 years?

Every time I follow this train of thought, I also end up pondering time’s arrow. I also wonder - since I’m conscious of typing this right now, can I assume that I will never get Alzheimer’s that will erase this precise moment from my memory?