I just put my child to bed. She's four now (four and a half, excuse me), and the glaring personality does not peak its head through the tiny little holes of the person she's becoming... it leaps through, tearing down walls with reckless abandon, and roaring a hearty bear/ lion/ tiger roar that only a child can demonstrate with as much charisma.
It amazes me, still, to reflect that she did not exist five years ago (at least, not in the way that we've come to define the word). My thoughts on reincarnation have to come into play here, however. How is it possible that this person, this soul, this energy did not exist before? That I and her mother created something so cosmic, so stupefying in its grandeur? From something so simple as a combination of bodily fluids that literally every human being who's ever graced the earth has? It's life!
Perhaps it makes more sense (or less, whichever you prefer) to propose that, while the specific combination of hereditary traits and environmental factors form her as from clay, the clay itself may have walked, talked, laughed, and loved before. Now, mind you, I grant this may be wishful thinking, given that her namesake was my childhood love, taken from this world (some say too early... who's to say?). Whichever side of the coin you choose to see, it's an intriguing question, and one that I'm sure will offer much introspection throughout my life, so long as I accept that I will never truly have the answer.