I have walked through many lives, some of them my own, and I am not who I was

I have walked through many lives,
some of them my own,
and I am not who I was,
though some principle of being
abides, from which I struggle
not to stray.
[....]
Though I lack the art to decipher it,
no doubt the next chapter
in my book of transformations
is already written.
I am not done with my changes.

- The Layers, by Stanley Kunitz