As are many of Dickinson's poems, "I dreaded that first Robin, so--" is essentially an elegy centered on the tension between life, as represented by nature, and death, as represented by the speaker, who describes herself explicitly in the sixth stanza
They're here, though; not a creature failedl
No Blossom stayed away
In gentle deference to me—
The Queen of Calvary—
The speaker, who, as the Queen of Calvary, is no longer a part of the living nature represented by birds and bees "and their unthinking drums" is at rest, wrapped in solitude and silence. The overt Christian reference (Queen of Calvary) is unusual for Dickinson but clearly places the speaker in the ground.
That the speaker initially wishes to be left in silence is clear from her fear of the robin whose song "hurts a little" but over time "I'm accustomed to Him grown," that is, as the robin grows during the Spring, the speaker is able to tolerate the birdsong. But in addition to dreading nature's song, the speaker fears...
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