The first line of the poem sets up the premise of "When I Have Fears." The speaker addresses when he "may cease to be," which suggests that the poem focuses on his worries concerning life and mortality (1). Much of this poem centers on the speaker's regrets of not accomplishing many of his dreams and goals, such as:
And when I feel, fair creature of an hour,
That I shall never look upon thee more (9-10).
Besides looking upon his beloved, the speaker of the poem also wishes to capture all his best ideas in pen from his brain, trace shadowy silhouettes from the clouds, and ponder the beauty of nature. The poem concludes with the speaker's desire to contemplate his regrets and dreams in solitude until the metaphorical end of time.