Why do you write?
Do you wish to share information?
Do you want to share someone's life?
Did you read something, and was left unsatisfied, so you have to tell it your own way?
Did you read book, and decided there needed to be a sequel?
For the fun of it?
Do you find joy in storytelling?
Because you can?
Inspiration from another's writing?
Escape?
Agenda?
Meditation?
To entertain those around you?
To make people laugh, cry, think, etc?
There are many reasons for writing. Choose carefully. There are reasons that will kill your story if you are not careful. Beware of agenda. Beware of rewriting other people's stories. These are very difficult to do successfully.
Tolkien wrote for the fun of it. Dickens wrote to get paid. Rowling wrote for her children. Austen wrote to provide decent literature.
Why do you write?