The world is constructed so loosely, isn't it?

It seems life
is constructed in a way
that no one can fulfill it alone.
Life contains its own absence,
which only an other can fulfill.
It seems the world is the summation of Others
and yet,
we neither know nor are told
that we will fulfill each other.
We lead our scattered lives,
perfectly unaware of each other...
Or at times, allowed to find
the Other's presence disagreeable
Why is it,
that the world is constructed so loosely?

images from movie kuuki-ningyo(air doll) site
soundtrack by World's End Girlfriend
english translation from wiki