AND WORLDWIDE SHIPPING
We should stop trying to answer this kind of question Boston Red Sox is my valentine shirt. It looks meaningful, but it’s actually not. I totally agree with everyone who said that it’s about your definition of the same but I want to take it a step further. I claim that there is no definition of same you’ll accept unless it matches the heuristics you already use to think about identity but if that’s the case, there’s no point in even looking for the definition.
I made the argument below in answer to a question about teleporting, but I think it applies to this as well Boston Red Sox is my valentine shirt. All these issues of identity in weird situations come from our reliance on gut feeling to determine whether or not someone is still the same person. That intuition evolved as a set of very simple checks to tell different people apart it was never meant to cover Greek ships or teleporters or half-brain transplants.
In questions like this, it simply isn’t useful. In other words: what happens when you’ve posted this kind of question? You probably try to define the same person and consciousness and all the other stuff you’ll need to get clear before you can start reasoning. And what happens when you try to find these definitions? If you’re anything like me or my philosophy classmates, the process looks something like this. You already know how you’ll make up your mind.