In his introduction to the 1997 anthology of American poetry*, James Tate talks about creating a poem, the hard work of setting forth and the desire for discovery. He points out that Columbus did not set out to discover America “but what he got was not so bad.” Tate is adamant about not imagining a whole poem at the beginning; he wants to discover.
Fiction writers would, I think, often add a proviso about knowing where a story is going, though many writers cast themselves into the unknown waters suggested by a character or a moment and see how things play out. Others — John Irving comes to mind — ponder the story until they settle on an ending.
Some writers believe that knowing the arc of the story makes for boring writing. I think it shouldn’t. Stories are not like how-to manuals on assembling a coffee pot. Along the way — as along any road or path — there are many things to discover and explore, including side paths that can alter major elements of the tale. In a story under construction in my own computer, I just found a very snoopy neighbor. I see mischief ahead, but I don’t know yet what it will be. And I know exactly how the story will end.
I like the shore-to-shore analogy actually, because so very much can happen during the trip across that lake or ocean.
*The Best American Poetry 1997, edited by David Lehman & James Tate