Doppleganger syndrome: The case of the 'Anti-ganger'

To believe that there is someone
in the big wide world
who looks exactly like you,
but is not the same
your ying and they're yang,
your a christian man
with a family and kids,
they're a satonist,
a murdering rapist
who butchers their victims
and bludgens their friends,
and all this time without
ever 'going round the bend'
some say it doesn't exist
but the question you have
to ask yourself is this,
can you have ying without yang
or hate without bliss