What made the poet happy?

William Wordsworth's "I Wandered Lonely as a Cloud" presents an idyllic view of the world around us. When the poem begins, the narrator focuses on feelings of isolation and loneliness, but even these feelings are tempered via the simile that is presented. Yes, the narrator is lonely, but "as a cloud," which suggests that there is still a light, airy feeling to the solitude. Any feelings of sadness are pushed away as the narrator describes a field of daffodils:

Beside the lake, beneath the trees,Fluttering and dancing in the breeze.Continuous as the stars that shineAnd twinkle on the milky way,They stretched in never-ending lineAlong the margin of a bay:Ten thousand saw I at a glance,Tossing their heads in sprightly dance.

The narrator goes on to discuss how the daffodils brighten the world, and the mood of the poet, by their very presence in it:

The waves beside them danced; but theyOut-did the sparkling waves in glee:A poet could not but be gay,In such a jocund company:

It is the daffodils that make the narrator so happy. However, the happiness is not
limited to the time that the narrator spends in their presence. Rather, it is something
that the narrator can tap into at any time, as Wordsworth establishes in the final lines:

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

Through the experience, the narrator learned to channel memory to conjure the happiness of the original "bliss of solitude" experienced in the presence of nature. This poem serves as a reminder that happiness can be found by allowing the beauty of the world to permeate through us.