I am not I by Juan Ramon Jimenez

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.

From http://www.poetry-chaikhana.com/J/JimenezJuanR/IAmNotI.htm