Most important of all, as a counterexample to Endymion, he had hit upon a style that suited him—language as compact and dense with imagery as possible, with not a single wasted line. With these lessons in hand, in the years 1818 to 1819, before he became gravely ill, Keats would produce some of the most memorable poems in the English language, including all of his greatest odes. This added up to perhaps the most productive two years of writing in the history of Western literature—all of it set up by the rigorous self-apprenticeship he had put himself through.
