Why do I write? I'd give a different answer to that question than to why do I have a blog.
So, JMH and Philippe, I write because I can't not write. The answer is something along the lines of yours JMH - I feel better when I write. Not in a self-psycho-analysis way, just in a constructive, creative way. I take an idea or a sentence or event that I like or don't like at all and work backwards to the beginning of a story or a tale or picture taken with words. It's an exercise I like, a task I enjoy. And I like being able to describe something really specific - experience or event or feeling - in a way that lets someone else read something entirely different and personal into it. Being able to share something that is both open and closed in nature. Something that, in the end, is both mine and yours.