What does the poet ask the bird to teach him in "To a Skylark"?

Shelley spends about the first third of "To a Skylark" praising the bird, saying it is "from Heaven" and "Like an unbodied joy." The skylark is depicted as perfect and otherworldly. Eventually, the poet asks the skylark what the bird can be compared to. What else functions in this way? And then at the end of the poem, the poet asks the skylark to teach him how to be more like the bird. The speaker writes,

Teach me half the gladness
That thy brain must know,
Such harmonious madness
From my lips would flow
The world should listen then, as I am listening now.

This final stanza of the poem is where the speaker explicitly asks the skylark to teach him the bird's ways. The poet asks the bird to instruct him in only "half the gladness / That thy brain must know." Shelley needs only that small portion of the "gladness," respecting and acknowledging that the bird will always have more power and grace than he can hope to have himself. If he had even half of the bird's skill, he would be able to compel "The world" to "listen" to his "harmonious madness." What he wants from the skylark is the ability to influence the world around him the way the skylark influences him.