I think a good writer is a mix of confidence (sure that what they're writing is going to appeal to their readers) and uncertainty (what if all these words are crap?). If you're too confident, you get an attitude that seeps through into your writing, affecting the characters and the story. If you're too uncertain, you'll never finish anything.
Composing gives me great pleasure. . . there is nothing that surpasses the joy of creation, if only because through it one wins hours of self-forgetfulness, when one lives in a world of sound.