John Keats wrote this sonnet in 1815 or 1816, and it is usually interpreted to be addressing his own insecurities in his own appearance, specifically he height: he was barely over five feet tall. In fact, this may be the only reason he didn't join the navy rather than turn to medicine: he was three inches under the minimum height requirement for naval officers.

It has also been proposed that this was the first of several of his poems on the subject of love between a fairy and a mortal ("La Belle Dame sans Merci", Endymion, "Lamia"). Perhaps Keats intended both meanings.

Had I a man's fair form, then might my sighs

Had I a man's fair form, then might my sighs
Be echoed swiftly through that ivory shell
Thine ear, and find thy gentle heart; so well
Would passion arm me for the enterprize:
But ah! I am no knight whose foeman dies;
No cuirass glistens on my bosom's swell;
I am no happy shepherd of the dell
Whose lips have trembled with a maiden's eyes.
Yet must I dote on thee,--call thee sweet,
Sweeter by far than Hybla's honied roses
When steep'd in dew rich to intoxication.
Ah! I will taste that dew, for me 'tis meet,
And when the moon her pallid face disclose,
I'll gather some by spells, and incantation.