Have you ever met with the concept of Ship of Theseus?
It goes like this - "If you replace all the parts of a boat, is it still the same boat?"
It's a common knowledge that various types of cells in our body keep getting replaced at some point in our lives. A common misconception would be another known curiosity, about the average human body supposedly replacing itself completely, on a cellular level, every seven or so years. While that could be probable, it was never truly proven.
However..
If all cells in our body were to be replaced at some point, would that anyhow affect your vision of reality? Your inner "you", your ID, the deepest of deep, the soul. What if everybody simply gets replaced with another being at some point in their lifes.. no, at few points. Perhaps all the sudden changes in behaviour and likings could be explained in different way than menopause, hormonal changes, growing up and midlife crisis.
Think about it.
Can you really say that whatever you seem to remember in your life's past, you have truly experienced? Perhaps it's happening even right now, a gradual change that slowly makes you lose control over yourself, only to be met with a sudden realization that you are very much no longer in charge. Soon enough, all that will be left for you is to observe as your life unfolds before your very eyes, perhaps the process would already be so deep, that it wouldn't raise any alarm, but surely, sooner or later, your very existence will simply vanish, like a thinning mist.