Sonnet 87 reads like a conclusion to the sonnet sequence describing the dominance of the rival poet, but in fact is the poet's farewell to the youth, who has returned to him but "art too dear" for the poet to possess. The theme of farewell unifies this sonnet; in varying degrees, farewell is alluded to in the following nine poems. When the friendship between the poet and the young man collapses, only then does the poet discover that the young man was merely a "dream." He concedes defeat and bids the youth a regretful goodbye.
In the sonnet's first quatrain, the poet unequivocally bids farewell to the young man. Surprisingly, the tone is even-keeled rather than melodramatic, as if the poet were simply stating a fact and then explaining the reason for it: "Farewell: thou art too dear for my possessing, / And like enough thou know'st thy estimate." "Dear" in the first line implies that the youth is both too costly and too much loved, and the legal terminology in the first four lines suggests how flimsy is the poet's right to possess the youth.
The second and third quatrains explain further the poet's reasons for saying goodbye to the young man. In the second quatrain, he characteristically reverts to questioning his own worth and rhetorically asks why he ever thought he deserved the youth's affections: "And for that riches where is my deserving? / The cause of this fair gift in me is wanting." The poet's eyes finally have been opened about his relationship with the young man, for in the third quatrain, he acknowledges that the strain in their friendship is the fault of both: "Thyself thou gav'st, thy own worth then not knowing, / Or me, to whom thou gav'st it, else mistaking."
The final couplet leaves little doubt that the poet no longer deludes himself about his and the young man's relationship. Surveying his past actions, the poet concludes that only two avenues — fantasy and reality — were ever open for him: "Thus have I had thee as a dream doth flatter, / In sleep a king, but waking no such matter." Sadly, neither fantasy nor reality offers the poet any consolation for the youth's emotional separation from him, for fantasy is make-believe, and reality exposes the gulf that exists — and always existed — between himself and the youth.