Writing Fiction: an Act of Willfulness?

In an interview in The New Yorker, Jhumpa Lahiri said:

"And yet writing stories is one of the most assertive things a person can do.  Fiction is an act of willfulness, a deliberate effort to reconceive, to rearrange, to reconstitute nothing short of reality itself."

She talked about being a non-assertive person and how writing became for her, a way of saying "Listen to me," when she was accustomed to just listening.

When I read this, I pictured her process of writing as an act of going outward, of reaching out to others, when my own process seems to be one of delving inward, and I wondered if the act of writing is the same for most writers, or a process that's as different as people are.  Do you feel that creating stories is an exploration of yourself, an expression to others, or something else entirely? 

When I write, I'm not thinking about readers or how it will be interpreted, but only of the creation and my intentions and hopes for it.  Thinking about readers comes later, in the editing, once I'm able to have some distance and apply practical considerations.  How much of this process is tied into the very nature of my personality, I don't know.  I am introverted and pretty self-sufficient.

How does your personality affect your writing; is it an outward process like Lahiri's or a journey to the center of you?