Samuel Taylor Coleridge wrote "This Lime-Tree Bower My Prison" after his friends went to take a day hike from his cottage. The day he wrote the poem, his wife had dropped scalding milk on his foot (on accident, apparently), so that he could not join his friends in their explorations. Coleridge was stuck sitting underneath a lime tree and thinking about all the breathtaking sights his friends would probably experience along their journey.
Together, Coleridge and William Wordsworth are the most important figures in the literary movement known as early British Romanticism. The early British Romantic poets were a cozy bunch, almost like a high school clique. They hung out all the time, wrote each other letters of admiration ("Your poetry is the best." "No, your poetry is the best."), and sometimes had their little tiffs and scrape-ups. They even had a clubby name, "The Lake Poets," because most of them lived at some point in the beautiful Lake District of England. In addition to Coleridge and Wordsworth, their circle included the poet Robert Southey, the poet and essayist Charles Lamb, and Wordsworth's sister Dorothy, an author in her own right.
"This Lime-Tree Bower My Prison" is addressed to Charles Lamb, who had come up from London to visit the group. Coleridge was sad that his run-in with dairy products prevented him with hanging out with Lamb that day. After he wrote the poem, Coleridge sent it to Southey in a letter. The letter itself is worth reading, if only as proof that the Romantics created as much simmering drama as a teen soap opera. (Coleridge used to idolize Southey, but then he came to see Wordsworth as greater and sent subtle hints to Southey about his change of mind, etc., etc.) Southey recognized the poem's brilliance and published it in an anthology in 1800. The poem most people read today is a revision that was re-published in 1834 in Coleridge's Poetical Works.
In 1798, a year after Coleridge wrote this poem, he and Wordsworth published the Lyrical Ballads. This collection really kicked off the Romantic movement and included two hugely influential poems: Coleridge's "The Rime of the Ancient Mariner" and Wordsworth's "Lines Composed A Few Miles Above Tintern Abbey."
Everyone knows the experience of being left behind, either on accident or (much worse) on purpose. The idea that your friends can have fun without you can be a blow to anyone's pride.
Samuel Taylor Coleridge's poem and letter are the only indication of how he felt when he was left behind by William and Dorothy Wordsworth and Charles Lamb on that lovely day when they took a walk to view the ocean. It doesn't appear that they deliberately cut him out of their fun, and Coleridge isn't resentful that they didn't stick around to tend to his injury. It would be one thing if Coleridge had lost his foot trying to rescue a cartload of schoolchildren; but having a skillet of hot milk dropped on you is not the kind of injury that gets fawned over. Still, you can imagine Coleridge's frustration. One of his best friends (Charles Lamb) comes to visit, someone he probably doesn't get the chance to see very often, and Coleridge misses the chance to bond over long nature-walks.
By writing this poem, Coleridge overcomes his disappointment. He comes to realize that the nature he sees around him is just as beautiful – if on a smaller scale – as the sights his friends are seeing on their walk. He also uses nature to connect himself to Charles when he decides to bless a bird that passes overhead.
So, to recap: everyone gets left behind at some point in life. We can either pout about it, or we can write a poem about our mystical union with the world…