Did Arnold succeed in making his pain go away and what universal lessons about pain can you draw from his example?

I would argue that through the course of The Absolutely True Diary of a Part-Time Indian, Arnold, also known as Junior, doesn't make his pain go away, but rather transforms his life into something better.
There are many sources of pain for Arnold throughout this novel, such as being rejected by his best friend Rowdy, when he decides to go to a different school, as well as the death of his sister. I think the universal lesson about pain we learn from this book is that although pain is inevitable, life goes on. Despite the fact that Rowdy rejects him, Arnold goes ahead with his plan to go to a new school, and he carves out a new life for himself there. Even though he is forced to face his former classmates as rivals on the basketball court and is knocked unconscious, Arnold continues to play ball. So, while pain is inevitable, it is also inevitable that life goes on.