The first stanza is filled with delightful images from the dreams of a seven-year-old child. These images are made up of scenes of adventure, similar to those which a child is likely to have read about in fairy tales. In his dreams, this child of the first stanza finds all sorts of adventures "so clearly in [his] head." These images contain dragons, castles, and all sorts of magic and enchanted towers.

The second stanza tells us what the same child experiences when he wakes up in the morning. When he opens his eyes, the magic is gone and the castle in his dreams is now just a chair. The fairies from his dreams have now disappeared and all the magical items that were part of his experience while sleeping have taken on an everyday, mundane appearance. The horsemen of his dreams are now ordinary boots, and the streams he saw while sleeping are "now a bath and water-can." In other words, he has come back to reality, and the line "I seek the magic land in vain" tells us that he's not happy about it; that he wishes he could have stayed in his dream world of magic and adventure.

There are two possible ways to read this poem. Firstly, it can be taken in the literal sense, as a child wishing to go back to the world of his dreams. On the other hand, it can also be argued that this poem is written from the perspective of an adult who is missing the overall magic of childhood.

Stevenson's poem describes the dream life of a seven year old. The first stanza has an upbeat, carefree tone; the child (the poem is in the first person) describes the dragons, "magic fruit," damsels in distress, and other fairy tale characters that he sees so vividly in his dreams when he goes to bed "at seven."

In the second stanza, the tone abruptly shifts; the child wakes up (also "at seven," this time in the morning) to find all the fancies of his dreams have been replaced with everyday items: instead of a castle, there is a chair; instead of a garden, there is a carpet. 

To me, the problem the poem poses is one of point of view. Even though it is in the first person, clearly the words and attitudes expressed are those of the adult poet, not a child. The wistful regret at the loss of the dream world expressed in the second stanza has more to do with Stevenson's own sadness over his lost childhood more than it applies to any actual feelings a real child might have.

This poem by Robert Louis Stevenson describes the nighttime fantasy world of a seven-year-old child and compares it to the mundane world of reality. The first stanza describes what the little boy sees as he drifts off to sleep and in his dreams. His mind has possibly been filled during the day with stories of fairy tales and games of pretend. As he is drifting off to sleep, he may see some dim shapes in his dark room that his mind imagines are elements of those stories, such as a castle and horsemen. While he sleeps, he dreams about the luscious fruits that grow in this magic kingdom and "fair maidens" who are trapped in a tower or magical forest. Everything seems so real to him.

When he wakes up in the morning, however, as described in the second stanza, he realizes as the light floods his room that the castle he supposed stood in his room is really just a chair, and the horsemen are his boots standing next to it. There is no longer an imaginary river, but only a "bath and water-can." He looks around his room hoping to find the magic of the pre-sleep and dream world, and sees no evidence of it. 

The poem brings to life the vivid imagination of a seven-year-old and the disappointment he feels when reality doesn't measure up to the beauty and excitement of his daydreams and night dreams. 

In his poem “A Child’s Thought,” Robert Louis Stevenson captures the musings of a seven-year child as he drifts off to his sleepy dreams. In the second stanza, he describes the child’s room as it sits the next morning.  The poem is written in couplets which provide a quick, child-like rhyming pattern.

The first stanza describes the young child’s dreams. The child sees castles, gardens, heroic horsemen, and ladies who need rescuing. There are “magic fruits” in the lush, imaginary land a seven-year conjures in his sleepy head.  

In the second stanza, Stephenson, describes how the child seeks that enchanted dreamland when he awakes. The child’s room is just as it should be with chairs, carpet, bath, and boots all in place. There are no gallant horsemen or damsels in distress.  It is the room of seven-year-old, not of his dreams.