While other ponies in Twilight's life have something special about them, Twilight is just a regular old unicorn. She certainly isn't special like Princess Cadence. Sure, her foalsitter always tells her she's special, but there is no objective logic behind this reasoning. And the upcoming Summer Sun Celebration might be fun, but it certainly can't help. How could somepony, proving she's the most special pony in all of Equestria, help Twilight find her place in life?
This story is a purely fluffy head-canon to connect the uncertain Twilight seen in the Canterlot Wedding flashback with the one seen in Cutie Mark Chronicles. It is not that serious, but I think it's nice.
If someone doesn't get it, think of Pinkie's hair being used as a cannon. That was the purpose of this story.