Mind boggling

Imagine a man who is on a long journey, on his ship. and a part of the ship breaks, so he chucks the broken bit of wood overboard and replaces it with a new bit of wood. I don't know, maybe he stopped at an island to get the wood. Anyway, a bit further on another bit of the ship is broken so he replaces that with a new bit of wood. It's still his ship, of course. And this continues, until by the time he reaches his destination, every single bit of the ship has been replaced by new wood.

The question is, is it still the man's ship? And if not, when exactly did it not become his ship? Because no part of it is the ship he started out in.

Of course, if the man had just scraped the whole ship in one go and bought another one, it'd be easy. The original ship would be dead and gone and the new one would be obviously a different ship. But the fact that it was gradual changes everything.

Well, it's the same with people. Am I the same person as I was a year ago, just with some new bits, or has so much of me changed that I am dead and gone and have been replaced by someone totally different? And when did I become not me?

i just thought this was an intriguing story...got the idea from the book Sleepwalking-by Nicola Morgan