Stories are hiding in all of us, I am convinced of this. Sometimes all it takes is the right prodding and nudging to get them to emerge. A writing prompt can sometimes get a new story possibility to show its face.
Here are a few to get you started . . .
Take the plot of your favorite movie and weave it into the plot of your least favorite movie. How does the plot change?
Now put a different twist in it. Take your most despised book characters and weave them into the plot of your favorite book(s). What changes? How do the rest of the characters' lives change? What problems arise?
One more: Your least favorite friend from school and/or your childhood shows up at your door, unannounced and completely out of the blue, on the hottest day of summer. Why is s/he there?