When Koboli was a fledgling he was a fantastic runner. Most Rito weren’t very good at moving on their feet since so much of their culture revolved around flight. Koboli really loved being able to run laps around all of the other fledglings. He would boast about being the best postman ever because of this.
Unfortunately, when he got his wings he found that his movement was stricken to his feet. He just couldn’t fly right. No matter how hard or hard he practiced, he was just a horrible and awkward flier. He was still a fast runner! But you can’t be a postman for the many island throughout the Great Sea just be running over the ocean.
So, he basically felt useless for a really long time. All he wanted to do was to be a postman. That’s when he put his thinker to the test and came up with the brilliant idea that was a post sorter! In the past everything was so unorganized, deliveries would often be late or even forgotten. Koboli figured that, if he couldn’t fly the post to people, he could at least sort everything to make sure it got to them.