When I start, and you stop;
or where you start, and I stop
I do not know;
and yet, it is not gray-
for we do not dance in black and white.
But if I search where I am, and you are not
I find no I that is where you are not.

Pablo Neruda seems to have some kind of amazing ability to capture the most personal of thoughts in beautiful prose:

SONNET XLV: DON'T GO FAR OFF, NOT EVEN FOR A DAY

Don't go far off, not even for a day, because --
because -- I don't know how to say it: a day is long
and I will be waiting for you, as in an empty station
when the trains are parked off somewhere else, asleep.
Don't leave me, even for an hour, because
then the little drops of anguish will all run together,
the smoke that roams looking for a home will drift
into me, choking my lost heart.
Oh, may your silhouette never dissolve on the beach;
may your eyelids never flutter into the empty distance.
Don't leave me for a second, my dearest,
because in that moment you'll have gone so far
I'll wander mazily over all the earth, asking,
Will you come back? Will you leave me here,
dying?