We started the poem at the beginning of the day and now end at night. Not only does this show the "circle motif" in this poem - what I mean is how "all things come to a close" and then restart anew - but it also parallels the journey of the youth, from being naive and blissful to being to falling victim to that naivety and becoming unaware of their fictitious bliss in the unknown; the journey leads to isolation from reality.

Doubt is fled seems very much like a point on the youths lack of internal questioning. They do not think there is room for doubt, as they must be right - a point made from their lack of understanding the nuance of truth and reality.

Does this mean that there is delight in not understanding truth? It is the youths who are delighted, relating to their lack of experience.

p.s This poem is taken from Selected Poetry and Prose of Blake (section Songs of Experience)

We start the poem at the beginning of the day, juxtaposing the youth that come hither. Just as the day begins, so do the youth with their lives.

The youth are at the beginning of their lives, and so the image of truth (reality as it is perceived universally) is also in its beginning stages, not fully developed nor fully understood by the youth.