Perhaps the best example of this is in the Wizard of Oz. Throughout the whole movie, Dorothy tells anyone who will listen that she wants to go home. That is her goal. She survives the obstacles in her way, including the wicked witch of the west. She and her friends go through trial by fire and water and opium (poppies). Trees lob apples at them. Flying monkeys kidnap Dorothy and Toto. They were locked out of the Emerald City and barred from seeing the wizard. And after all that hard work, when what she wants is within reach, the balloon leaves without her and ALL IS LOST!

It made for a heartbreaking scene.
And a much more powerful scene.
But my heroine returned stronger and the bonds of friendship were strenthened.
I'm so glad someone pointed this plot manipulation out to me. What a powerful tool!
And of course, Dorothy had the power all along to get what she wanted.
But she had to go through the journey, following the yellow brick road, until she figured it out for herself.
Just like our characters.
Just like us.
It was quite an epiphany for me. Have you had any writerly epiphanies? What were they?