Philip Kindred Dick and his twin sister, Jane Charlotte Dick, were born six weeks prematurely on December 16, 1928 in Chicago to Dorothy Kindred Dick, and Joseph Edgar Dick who worked for the United States Department of Agriculture. Jane died six weeks later on January 26, 1929. The death of Philip's twin sister profoundly affected his writing, relationships, and every aspect of his life, leading to the recurrent motif of the "phantom twin" in many of his books. (from: en.wikipedia.org/wiki/Philip_K._Dick)
the survivor of this type of early twin loss is called a twinless twin.
lyrics
when i was a boy
there was also a girl
a nameless face
that speaks to me sometimes
she has grown up
in my mind
and in my ears
i hear her sometimes
twinless twin
she is mine
twinless twin
i am hers
i was a struggling ... child
it's natural to fight
to survive
but there was only
enough love
and time
for one of us
twinless twin
she is mine
twinless twin
i am hers
when i was young
i survived
but i'm not
sure why
and i give everything
that i have
and one night i find that i've
given it all to her
now i'm with my
twinless twin
she is mine
i am hers