I'm not sure exactly as I don't know who Bob is or what his unfinished story is about. Maybe it could be about his unfulfilled dreams, an event that was interrupted in his life. Without more context, it's hard to say for sure.
It could be significant as it might show Bob's creative process, even if it was unfinished. It can give us an insight into how he thinks and approaches storytelling.
The song is based on Rubin Carter's story. Carter was a boxer with a promising career. However, he was wrongly accused of a triple murder in 1966. The trial was full of problems, including possible racial prejudice. Bob Dylan learned about Carter's case and was outraged by the injustice. So he wrote 'Hurricane' to raise public awareness of Carter's situation, hoping that justice could be served eventually.
Well, 'Girl from the North Country' tells a story that is filled with a certain kind of rural simplicity and a touch of lost love. Bob Dylan's lyrics paint a picture of a place in the north where this girl is from. The song might be based on someone he knew growing up. It has a very folksy feel to it, which was characteristic of Dylan's early work. The melody and the lyrics together create an atmosphere of wistfulness, as if he's looking back at a time that can't be retrieved, and this girl is a symbol of that past time.
Well, Half Life's story could be considered unfinished. There haven't been direct sequels that tie up all the plot threads. It leaves fans craving for more closure and explanations.
The real story of 'A Street Cat Named Bob' is about a homeless man and the stray cat that changed his life. It's a heartwarming tale of companionship and recovery.