I think the bravest thing a writer can do is write the damned book.
In our minds, the story is perfect with the promise that, when we tell it, it will flow like liquid gold. The truth is that the moment we put words on paper, the story curdles--the nebulous becomes murky, the flaws embarrassingly obvious, the plot too thick and the characters too thin--and yet if we don't brave the fog, the story will never be told. If we don't keep digging, we'll never discover the nuggets of gold worth keeping. If we don't build our castles, we won't have anything to knock down and rebuild better and stronger than before. It's tough to dive in, knowing that it will be a treacherous road doomed to be torn up, ripped out, redesigned and overhauled with more than one bypass, shortcut, dark alley and dead end...but "The End" is worth the journey. Honest.
Step by step.
Word by word.
Bird by bird.
And as they say in The Hobbit: we're off to have an adventure!