The song captures a moment of total vulnerability where he felt like "a dog of no one barking at the doors of heaven". Shortly after the album's success, Sabina suffered a stroke (infarto cerebral), making this song the "swan song" of his wildest era.
The title highlights a sharp irony—it only took her 19 days to move on and find someone else, while it took Sabina 500 sleepless nights to even begin to forget her. The Deeper Meaning Joaquin Sabina - 19 Dias Y 500 Noches (Video Oficial)
The end of the relationship was as dramatic as the song suggests: The song captures a moment of total vulnerability