I am not I.
I am this one
walking beside me whom I do not see,
whom at times I manage to visit,
and whom at other times I forget;
the one who remains silent while I talk,
the one who forgives, sweet, when I hate,
the one who takes a walk when I am indoors,
the one who will remain standing when I die.

Juan Ramón Jiménez

http://www.poemhunter.com/poem/i-am-not-i-3/