Why write?

Ok, many fellow authors tell me they write for the love of writing, the passion and the desire to put their own words down on paper. I suppose it's the same as an actor, always wanting to be on stage, but is this true? If one writes a book that no one reads, is it really a book? Or is it simply a waste of time?
Personally I write for gain, I'm being honest, I write books to sell books. I don't seek fame in todays conception of the word, but I would like my writing to be recognised and more important, paid for. I realise this may not be the ideal of an author, picking up quill, pen, typewriter or personal computer, but it is fact. It is a fact for me and if truth be known, it is a fact for all writers.

My latest book is not selling much as yet, but it's barely a month old so that's understandable. My very 1st book, A Fly on the Ward is still selling nicely, obviously I did something right there. But why do I continue to write? In truth I have no idea. Health limits me to what I can and cannot do and writing seemed a possible avenue of funding in order to 'keep the wolf from the door.' Perhaps a gun might be a better idea? For the wolf of course, not me, said Little Red from the Hood.

The book market is swamped these days, anybody and anyone can and will write a book and through the modern ability to self publish, many new authors spring up every day. So why do I write? Any answers yet?
Maybe I don't sell many books simply because I'm rubbish at putting stories on paper? Maybe my eclectic range of books puts people off? I have written humorous short stories, one academic book, two children's books and now I'm editing the second of my science fiction novels. Maybe I should have stuck to funny hospital stories, people certainly appear to like anything related to hospitals? The answer is, I don't know. I decided Animan ll would be my last book, but will it? Ideas abound in the empty space of my mind every moment of the day, surely there's something there worth writing about?
I admit to have enjoyed the purpose writing gave to my life. I am restricted in what I can do and spend a lot of time home on my own with only me for company. Perhaps writing keeps me sane? Perhaps not. What would I do if I didn't write? Probably become addicted to day time television.
Lord forbid!