John Keats wrote this sonnet in 1818, after visiting the home of Robert Burns, which had been turned into a whiskey shop. He was so unhappy with it later that he burned it, the only poem, that we know of, that he ever took the effort to destroy, besides some of his earliest poetry several years before. Fortunately his friend and travelling companion Charles Brown had made a copy first.
While this is certainly not among is best work, it's nowhere near his worst, either. There were poems much worse than this one that he let stand. The only clue we have as to why he felt the need to destroy this one is the first line. "This mortal body of a thousand days" echoes a strange fear that haunted Keats in 1818 that he had exactly three years left to live. As it turned out, he didn't have that long.
This mortal body of a thousand days
This mortal body of a thousand days
Now fills, O Burns, a space in thine own room,
Where thou didst dream alone on budded bays,
Happy and thoughtless of thy day of doom!
My pulse is warm with thine old barley-bree,
My head is light with pledging a great soul,
My eyes are wandering, and I cannot see,
Fancy is dead and drunken at its goal;
Yet can I stamp my foot upon thy floor,
Yet can I ope thy window-sash to find
The meadow thou hast tramped o'er and o'er,--
Yet can I think of thee till thought is blind,--
Yet can I gulp a bumper to thy name,--
O smile among the shades, for this is fame!