In the poem "Daffodils" by William Wordsworth, the poet reflects on the impact that the memory of the sight of the daffodils has on him. The poem describes how, when the poet is in a contemplative or pensive mood, the memory of the field of daffodils he once encountered flashes upon his inward eye. The recollection of the scene brings about a profound and positive change in his emotional state.

The specific lines from the poem that address this transformative effect are:

"For oft, when on couch I lie
In vacant or in pensive mood,
They flash upon that inward eye
Which is the bliss of solitude;
And then my heart with pleasure fills,
And dances with the daffodils."

In these lines, Wordsworth describes how, during moments of solitude or contemplation, the memory of the daffodils fills his heart with pleasure. The recollection becomes a source of joy and inspiration, and his heart metaphorically "dances with the daffodils." This reflects the enduring power of the memory, illustrating how the beauty of the natural scene continues to uplift and bring happiness to the poet even in moments of quiet reflection.