Writing fiction is interesting. You want to tell a satisfying story. You can only do this if you can create a satisfying arc for your main character. Which means taking them from one point to a different point where they have learned an important lesson or grown in some meaningful way, and demonstrated their growth through their actions. Essentially, along the way you need to teach your main character the secrets of the universe. Yesterday I was teaching my main character that love is unselfish. That when you truly love, you are willing to sacrifice for the people you care about.
You don't spend that kind of time considering these kinds of moral values without being changed. It's one of the things I love most about writing. Yesterday night I was sick. I felt miserable. And I wanted to go to bed. But my husband had worked late and the house was a wreck. Remembering the lessons I'm trying to teach my main character, I spent an hour sacrificing sleep, and cleaning so Cody could come home to a peaceful house.
And it was satisfying.
Like a character arc that really works!