I Dreamed that I Was Sound Asleep

I dreamed that I was sound asleep
and lying in my bed,
and in my dream another dream
was drifting through my head.

And in that dream I had a dream
and in it I was dreaming
a dream about a dream until
I woke up nearly screaming.

It seems to dream you’re dreaming
is a terrible mistake.
I can’t tell which dream ended
and I’m not sure I’m awake.