This composition is one of Chopin's most famous, which is why it surprises most people to know it was never published in his lifetime. In fact, he instructed his pupil, Julian Fontana, to destroy the piece. It is not known why, but many speculate that he did not want the piece published for fear that some might say he had plagiarized Beethoven's Moonlight Sonata - this is because a passage in measures 7/8 (and repeated throughout the piece) is identical to a mini cadenza that exists in the third movement of Beethoven's famous work (measure 187).