Why did Keats write in a lyrical fashion in "La Belle Dame Sand Merci"?

I am currently doing a english essay on this poem and have written that "Keats made a concious choice to write in a lyrical, romantic fashion" but I havent written why. I'm sure I knew at the time, but I can't remember now and I like to have a reason to back up my points. Any help would be appreciated. Thanks for reading.|||He was dying, and had yet to really be 'in love'; that was enough to make anyone rather soppy about matter upon one was ignorant. Eventually he was rumored to love, but for the most part he experienced life much in a doe-eyed and hopeful, and a bit tragic fashion. His poems on the idyllic appreciation of nature are akin to what Monet's paintings would be if translated into the written language: swett breezy scenes of rest and good company. Things for which he longed for much but rarely saw. That would tinge anyone's writings with a bit of sashaying romance, says I.