Studies have shown that you’re more likely to be happy if you have happy friends, and I’m sure that’s true for writers too: Surround yourself with happy writers and you’re more likely to be a happy (and productive!) writer yourself.
I love writers who choose to be optimistic even though writing can be difficult and frustrating. One such happy writer is Nathan Bransford. I enjoyed his book How to Write a Novel: 47 Rules for Writing a Stupendously Awesome Novel That You Will Love Forever. The value of this book isn’t based so much on the writing concepts themselves, but on Bransford’s ability to convey the writer’s life in an honest yet optimistic way (read the Table of Contents for proof).
I recommend both Bransford’s book and his 2009 blog post “Ten Commandments for Happy Writers.” As Bransford says:
[B]elieve it or not, writing and happiness can, in fact, go together.