That's a fine point about gradually replacing the brain, one I'd never thought of in all my time thinking about this dumb, made up sci-fi question. Maybe that's just how I'll imagine it happening in "San Junipero."

Yes, someone mentioned Soma elsewhere in the comments, and it was definitely on my mind throughout (if anyone reading hasn't played it: Soma comes down pretty explicitly on the other side: the uploaded version of you is a second, separate duplicate that you do not experience).

Dissenting opinion: I didn't think this episode was optimistic at all. In fact, I think it may represent the biggest trap Black Mirror has dealt with so far. Let me explain.

Stabbing Dodd in the chest… it fills you with Determination.

I never catch things like this, so I was really happy that I was thinking of Gift of the Magi all the way through without knowing the title of this episode.