Because God gave you your makeup and superintended every moment of your past, including all the hardship, pain, and struggles, He wants to use your words in a unique manner. No one else can speak through your vocal cords, and, equally important, no one else has your story.
When you have a sense of calling, whether it's to be a musician, soloist, artist, in one of the technical fields, or a plumber, there is something deep and enriching when you realize it isn't just a casual choice, it's a divine calling. It's not limited to vocational Christian service by any means.
We cannot change our past. We can not change the fact that people act in a certain way. We can not change the inevitable. The only thing we can do is play on the one string we have, and that is our attitude.