Sad is beautiful

I'm sad,
really sad,
about something that i want to keep it to myself,
so lets call it a secret,
like the woman
i saw on the highway,
either her face
or her body i can't recall,
neither her feeling
nor my emotion i can't forget,
as rain was pouring,
and my windshield was blurring,
then lightning was hitting,
and thunder accompanying without any sign of stopping,
the steady steps she took in the rain
described everything but explained nothing,
everyone notices,
but no one knows why