[stickfigure]

I hate to be the one to tell you but...

Every time your loved one respirates, ingests food, and defecates, a portion of their body is replaced. The material person you know now may be completely different from the person you fell in love with.

[sumy23]

It's not about the physical material, but rather the history, like the ship of Theseus.

[AnIdiotOnTheNet]

The whole idea of The Ship of Theseus is to show how silly this line of reasoning is. There is no Ship of Theseus, there is only our illusion of it.

[sumy23]

The Ship of Theseus is not a parable. It doesn't have a lesson you're supposed to take away from it. There are different of ways of looking at the problem. The "solution" that appeals to you is probably a reflection of how you think, but there isn't one "right" answer.

For example, one answer is to look at the ship as a 4-dimensional object (the three spatial dimensions + time). Yes, the material in the 3D slice at t0 is different than at tN, but you're still looking at slices of the same object.