Writing What I Know

There are many words of advice given to writers as they learn and hone their craft. One phrase consistently tends to pop up: "write what you know." What does that mean exactly? If every author followed that advice literally, how could we have wonderful fantasy worlds like those of Lord of the Rings or Hunger Games? Or intriguing murder mysteries?

"Writing what you know" is more subtle than that. I may not know what it's like to come upon a dead body, but I do know what it feels like to be...