Keats, with presentiments of his early death, worked with single-minded dedication once he began writing poetry at the age of 18. He began a rigorous training period during which he studied the great poets who preceded him, and in his November 1817 poem, Sleep and Poetry , he wrote: O for ten years, that I may overwhelm/Myself in poesy; so I may do the deed/That my own soul has to itself decreed. Alas, he was to have only three years before he became ill with the tuberculosis that would finally kill him at 25. Keats is celebrated for his sensual imagery, his intense identification with the things he wrote about, and the beauty of his language, which has often been compared to Shakespeare`s.