Write what you'll know about tomorrow.

I was participating in a conversation recently about motivating young adults to write. Someone mentioned when they address young writers on this subject they suggest they only take on subjects they know, and not venture into unfamiliar waters; siting the fear of discouragement as the reason. I was quite surprised at this, especially coming from an author. My argument was that a young writer should never limit themselves to only what they know. The whole idea seemed preposterous to me. How...