Analysis of Why Silent?

Why am I silent from year to year?
Needs must I sing on these blue March days?
What will you say, when I tell you here,
That already, I think, for a little praise,
       I have paid too dear?

For, I know not why, when I tell my thought,
It seems as though I fling it away;
And the charm wherewith a fancy is fraught,
When secret, dies with the fleeting lay
       Into which it is wrought.

So my butterfly-dreams their golden wings
But seldom unfurl from their chrysalis;
And thus I retain my loveliest things,
While the world, in its worldliness, does not miss
       What a poet sings.