Disclaimer: I'd say it is, But that's a lie, It's really his. Ouch, that's a bad one.
Spoilers: You don't really have to have seen "What Is and What Should Never Be", but it might make the meaning a little clearer.
A Glimpse of Heaven
--
I've seen a glimpse of heaven,
Of grass so green,
Of skies so blue.
Oh how I wish
That it were true.
--
I've seen a glimpse of heaven,
Of my mother's loving smile,
Of my lover's evening kiss.
It seemed so real
This simple bliss.
--
I've seen a glimpse of heaven,
Of what I wish,
Of what I need.
My hidden desire
For which I plead.
--
I've seen a glimpse of heaven,
Of an incomplete reality,
Of a gilded golden cell.
I saw Heaven
And returned to Hell.
A/N: My first "Supernatural" poem! I just watched season 2, episode 20, "What Is and What Should Never Be" and was inspired. Boy that was good acting! In case you didn't figure it out, this is Dean.