Keats’s "Ode on a Grecian Urn" is an example of ekphrasis, or a work of art about another work of art in a different medium. It’s a poem about an sculpted urn. One of the first and most famous examples of ekphrasis is Homer’s description of the Shield of Achilles in The Iliad. (Source)
Keats was trained as an apothecary, which was like a pharmacist back in the day. In response to one of his first publications, a magazine critic wrote: "It is a better and a wiser thing to be a starved apothecary than a starved poet; so back to the shop Mr John, back to ‘plasters, pills, and ointment boxes.’ " Ouch. (Source)
The uber-Romantic English teacher played by Robin Williams in the movie Dead Poet’s Society was named John Keating. We assure you: this is not a coincidence. Seize the day! (Source).