Imagine that you own a ship. You have named it Josefin. She is in excellent condition and you sail with her as often as you can, one time you even took a trip around the world with her. A wonderful ship.
Now, after a few years your fequent use of your beloved ship takes its toll and you have to fix her up and replace some parts. This you do regularly. Fixing and replacing parts that needs to be replaced and 20 years after you bought the ship every single part of the ship has been replaced with new ones. There isn't even a nail or a screw left from when you bought it.

Is it still the ship Josefin?

If not, when does it stop being Josefin? Is it when more then 50% of the ship is replaced or when the last original piece is removed?

If it still is Josefin, what would happen if you took all the old replaced parts and put them back together again? Which one would be Josefin?

It's just a name...

Ah, the "Ship of Theseus!" One of my favorite classical paradoxes! I ponder this one a lot, because in many ways, it is similar to a question which for me is, perhaps, the thing I would most like to know:

If we achieve the ability/technology to transfer individual consciousness into a clone body; or to upload it into a virtual world; or to replace the brain with a manmade (mechanical) analogue; --- will the "you" that wakes up from the procedure be the same "you" that went under anaesthesia? Presumably to others, you would be just the same because you would have every tiny nuance of experience and character as before. But would your individual awareness continue, as it does after regular surgery? Or would it simply be someone else, a new awareness, who believes they're you?

In the case of the "Ship of Theseus," and in your hypothetical case as well, I believe that the vessel is still the same because by whatever name it is called, it represents a conceptual entity which is not dependent on its physical components.

This isn't the best analogy, but take the Burning Man. Every year they go out onto the desert and burn an effigy which obviously must be made out of different wood each year. Yet each time it is the same Burning Man, because the wood and so forth represent a conceptual entity.

In the last instance, if the sum of the replacement parts was still the same ship, and you took the old parts and put them back together, that ship would be the same ship too. But I wouldn't try to sail in it.

There is only awareness, not "this awareness" or "that awareness" which refers to "awareness of X" and "awareness of Y".

The question is, why do you call it "Josefin"? In that lies the answer to the paradox. Names, names, names. Paradox arises when you have all the information and confuse it for less than all the information. If your knowledge encompasses something, there is never a paradox, only constructions of logic.

Imagine you are staring at an exact copy of yourself, brain experience, everything. That person is conscious, and you are conscious, but your conscious experience is separate, meaning that you are separate people.

you've been reading my erotic-fantasy blog!!!

Technically speaking, i think it´s no longer the same ship, the moment you´d replace a single molecule of it....having defined it as all of these specific molecules, joined in this specific manner.

so if a human ever has a molecular change, it is no longer the same human?
sounds reasonable...

The first one is Josefin, even with all the replaced parts.
The second one will also be Josefin.

Why not have two?

Yes, i once looked at a photo of myself 20 years younger....turns out that i was a lot smaller then