This quote by John Steinbeck is sound advice and a good idea to try. A writer that can write without restraint will surely be surprised by what they can achieve. Having an end goal is good but don’t let it dictate the progress you are trying to make. Writing is an ever revolving door of editing and revisions. Change is a given when you undertake a piece of writing. The more you limit your writing, the less room it has to flourish. Take it one good sentence at a time, one good paragraph at a time, one good scene at a time, one good page at a time. Give yourself space and time and you’ll be in for a worthwhile surprise.