The main theme of "When I Was Fair and Young" is regret. The poem is often attributed to Queen Elizabeth I, who reigned for many years as the queen of England but never married or had children.
The poem begins by describing how beautiful the speaker was when they were young, and how they dismissed anyone who tried to approach them by saying, "Go, go, go, seek some other where, importune me no more." This line ends every stanza of the poem.
The speaker then describes how much their rejection hurt those people, causing them to "weep" and "sigh." Despite all the grief the speaker causes, they continue to dismiss those who approach, saying, "Go, go, go, seek some other where, importune me no more."
Then the speaker is struck full of love, personified by a vengeful Cupid. Cupid is the son of Venus, the Roman goddess of love. Cupid causes the speaker to feel regret by "plucking" their "plumes," or taking away the things that the speaker was so proud of. Cupid says to the speaker, "Go, go, go, seek some other where, importune me no more."
The poem ends with the speaker reflecting on how much they have changed since they were young. Now the speaker is so full of love that they cannot sleep, and they regret dismissing all of the people who were in love with them earlier. Specifically, the speaker regrets that they ever said, "Go, go, go, seek some other where, importune me no more."
The repetition of the final line in each stanza highlights the regret the speaker feels. The line is initially said proudly by the speaker, then is claimed by Cupid, and finally is used to show how far the speaker has come from when they were younger.