So...if you're considering writing or having trouble with your current project, listen to the wise words of Mr. Twain.
You: No one sees me as a writer. I've been told it's a waste of time.
Mark Twain: Keep away from people who try to belittle your ambitions. Small people always do that, but the really great make you feel that you, too, can become great.
You: I have an idea, but how do I write the book?
Mark Twain: The secret of getting ahead is getting started. The secret of getting started is breaking your complex overwhelming tasks into small manageable tasks, and then starting on the first one.
You: I'd be so embarrassed if I tried to write a book and couldn't--or wrote it and no one wanted to publish it.
Mark Twain: Twenty years from now, you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.