A writer can't just be well-educated or good at research; to build a living, breathing world with interesting characters, you have to write from the gut. I'm not saying you have to live your life like a fantasy adventure. The trick is the ability to synthesize your own everyday experiences into your fiction. Infuse your characters with believable emotions and motivations. Infuse your world with rich sensory detail. For that you have to be in touch with your own existence and your own soul, the dark and the light of it.
Lynn Flewelling