Earlier quoted context omitted.
I am reminded of this quote: “This, milord, is my family’s axe. We have owned it for almost nine hundred years, see. Of course, sometimes it needed a new blade. And sometimes it has required a new handle, new designs on the metalwork, a little refreshing of the ornamentation . . . but is this not the nine-hundred-year-old axe of my family? And because it has changed gently over time, it is still a pretty good axe, y’…
What you’re describing is also known as Theseus’ Paradox, and has been with us for 2 millennia. http://en.wikipedia.org/wiki/Ship_of_Theseus
Thanks for the link to something much, much older.