I sleep if I dream, I do not know on waking...

I sleep.
If I dream.
I do not know on waking
What it was I dreamt ?
I sleep.
If I do not dream,
I waken in an open space -
I do not recognize, because I woke
to what ?
I still don't know
What's best is neither:
Dreaming nor not dreaming
And perhaps never waking...