A Poem Speaks

I watched the movie "Spender In The Grass" and there was part of a poem there that I wanted to read.
When I found it, it was not a poem, it was an ode.  I usually don't try to interpret poetry.  I just want to
enjoy it but for some reason I want to understand this ode.  The second verse is"

The rainbow comes and goes and lovely is the rose
The moon doth with delight look round her when the heavens are bare;
Waters on a starry night are beautiful and fair;
The sunshine is a glorious birth; but yet I know where'er I go
That there has past away a glory form the earth.

Did he write this when he was an old man and had lost many people he had loved?
He says again later in the poem:  Whither is fled the visionary gleam
Where is it now, the glory and the dream?
And the title of the movie was taken from this part:

What though the radiance which was once so bright, be now forever taken from my sight
Though nothing can bring back the hour of splendour in the grass, of glory in the flower
We will grieve not, rather find strength in what remains behind.

 He talks later on in the ode of the faith that looks through death
Perhaps if I was still young, this poem would not speak to me the way it does today.
So I believe William Wordsworth was an older man when he wrote this ode.
The best part of the movie was finding this ode.