Suppose you run an empire. There is no competitors east but there is a larger and more powerful force in the west so you move your territory east and east every time, adding new territory to the east and removing those in the west. You are adding eastern soil to your collection, removing western ones so they are not yours anymore. This happened, well kinda. The Huns used to live in where Russia is now, but now their descendants live in Hungary with no territorial overlap.
If one component of the ship is removed, it is no longer yours, whereas the replacement of it is yours. That set becomes you, removing one element and adding another, recognizably. If another ship is built after complete replacement that it looks identical, it comprises of elements all of them being rejected away from you. Since none of them is now a part of you, that ship is not you. Instead, you should be the other ship, with replacements for all elements, because that set was from the beginning you and only removed and added elements revised onto it. A folder does not automatically change its name even if you delete all files and add new ones.