Was there a more romantic Romantic than John Keats? The arrival of each winter, a time when the world seems quieter, invoking introspection, gets me thinking of the poet and what we might call the Keatsian model of the heart. This winter, there is even more pull, as it was 200 years ago, around this time in 1819, that Mr. Keats was acutely aware of three things.

One: He loved a woman, with a great, unslakable ardency, named Fanny Brawne. Two: He had it within himself, despite not having risen to this level before, to write the greatest odes in the history of English literature. And three: He was dying of the consumption that had long shadowed him, a reaper’s scythe hovering over its quarry.

Fanny and John were neighbors. At first, she thought little of him, but his devotions won her over. At one point, they were engaged, before Keats’s consumption worsened, at which point both knew that theirs was a star-crossed love. It may also be the most fruitful love in literature. For Keats concentrated on showing this woman, before he left this mortal coil, what she meant to his heart, his soul, his art. There are muses, and then there is what John Keats saw in Fanny Brawne.

F. Scott Fitzgerald remarked that he could not read “Ode to a Nightingale” without crying. Nor can I. Can you? Try it. Before 1819, Keats had secured a place in the poets’ pantheon, but it was a lower place. He would not have been well enough known for us to do a piece like this in a venue like this, which both breaks my heart — in a retroactive, counterfactual way — and instills in it gratitude for what he did in his annus mirabilis.

The most singsong of these masterpieces, and the perfect Valentine’s Day poem, is “La Belle Dame Sans Merci,” which translates to “the beautiful lady without mercy.” You know what I’m saying, fellas. Or do you? For this is not a poem about a woman who mistreated a man, but rather about a muse who, let us say, becomes entangled with an artist to produce something larger than them both. It is one of the most erotic poems in literature.

“O what can ail thee, knight-at-arms/Alone and palely and loitering?” a passerby asks our down-in-the-dumps knight-poet, who then proceeds to tell a tale of a woman — a spirit, a muse, a kind of post-human — who emerged from the bracken and conjoined with him. She hooks him up with tasty roots (read into that what you will), and he makes a garland for her hair. “I set her on my pacing steed, and nothing else saw all day long/For sidelong would she bend, and sing/A faery’s song.”

The charged eroticism of these lines has something supple about it — they have the gravity of grace, too. This is vulnerability and risk, a giving of one’s self to another, an ecstasy of faith that may well not be rewarded according to conventional expectations. But is happily-ever-after the reward, or is the reward the earned knowledge that in this non-guaranteed affair of the heart — as all such affairs are — this person drank life to the lees and became more human in doing so?

The forest siren takes the knight home with her. Up until this point, what has been happening has been right out in the open, on the side of the road. It has always struck me that this knight is telling his story to a passerby. He is electing to share something of himself, with little prompting. It almost feels like heroism.

The knight’s tale concludes with the beautiful lady disappearing, their encounter having been finite, the repast of his heart and mind, infinite. So he is going to stay where he is awhile and mull.

“And that is why I sojourn here,” he concludes. What a verb. Sojourn. It carries within it the idea of residence, of inhabitation. What has happened will always stay inside of me. Now, that’s a valentine from one who knew.

Colin Fleming’s fiction appears in Harper’s, and he writes on many subjects for many venues. His next book is “Buried on the Beaches: Cape Stories for Hooked Hearts and Driftwood Souls” (spring 2019).