If you are a plotter (a writer that likes to work on your plot usually via an outline before you start writing), or a plotter once the whole thing is written (using the exercise to make your story as strong as it can be), then this post, along with the others that K.M. Wieland has written (or will write) will be very helpful.
I liked I liked her line: The First Plot Point may take the protagonist to a new place, but the Third Plot Point makes him into a new person.
K.M also has a great archive of movie and some book plot points that can help you when you’re struggling with your own manuscript.
Deepen your understanding of story structure by examining the parallel functions of the First Plot Point and the Third Plot Point.