I love those books and movies that show a character getting a chance at a do-over in some area that he or she has regrets. Even though it seems like a dream come true, more often that not in storytelling, trying to erase regrets usually backfires. The character tries to do better, but actually ends up doing much worse in the process. BEFORE I FALL by Lauren Oliver is a great example of this.
Today give one of your characters a do-over. What does he or she wish they could have a second shot at, beyond anything else? Will it work out like he or she expects? How could this do-over end up making your character's life much, much worse?