Madeline L'Engle writes eloquently about this in Walking on Water: Reflections on Faith and Art.
"Only the most mature of us are able to be childlike. And to be able to be childlike involves memory; we must never forget any part of ourselves. As of this writing I am sixty-one years old in chronology. But I am not an isolated, chronological numerical statistic. I am sixty-one, but I am also four, and twelve, and fifteen, and twenty-three, and thirty-one, and forty-five, and ... and ... and..."
"If we lost any part of ourselves, we are thereby diminished. If we cannot be thirteen and sixty-one simultaneously, part of me has been taken away."