I draw the line in the sand and say that is different because sleep has been working "forever", while the quote in the parent comment describes a process that, not only does not exist and therefore work now, if it ever gets to work, we won't know if it's the same as the daily process that happens when we sleep.

Otherwise I actually agree with your point ("every night another little death", as the Sonic Youth song says): I'm different every morning. Usually, the differences are subtle. Over the time span of a lifetime though, I've been through enough changes that I often say ghosts of former selves share this body, and what "I" am now will probably be another ghost by the time the biological substrate dies and takes whatever "I" will be then, along with all the ghosts, with it (in my case we'll go up in smoke since I'll be cremated).