Shakespeare’s speaker is in a deep, lonely slump—feeling disgraced, ignored, and bitterly envious of almost everyone. He pictures himself weeping alone, cursing his luck, and longing for the talents, friends, and opportunities that others seem to have so easily. Even the things he usually enjoys leave him dissatisfied. The mood is heavy with self-pity and isolation, the kind of raw, late-night despair that makes the world feel deaf to your cries.
Then, in a heartbeat, the whole emotional weather changes. He suddenly thinks of the person he loves, and the simple memory of that love lifts him. He compares his spirit to a lark rising from the dreary ground at dawn to sing at heaven’s gate. That remembered sweetness makes him feel so wealthy inside that he wouldn’t swap lives with a king. The poem moves from utter wretchedness to an almost giddy, defiant joy—all sparked by the thought of someone who matters.