Write to think
The reason I've spent so long establishing this rather obvious point [that writing helps you refine your thinking] is that it leads to another that many people will find shocking. If writing down your ideas always makes them more precise and more complete, then no one who hasn't written about a topic has fully formed ideas about it. And someone who never writes has no fully formed ideas about anything nontrivial.
It feels to them as if they do, especially if they're not in the habit of critically examining their own thinking. Ideas can feel complete. It's only when you try to put them into words that you discover they're not. So if you never subject your ideas to that test, you'll not only never have fully formed ideas, but also never realize it.
Writing is a miraculous technology to support exploration and discovery, enabling a kind of gradient ascent in human understanding. You make tiny improvements, over and over. It may be a word or phrase you throw out and replace with a better; it may be an entire book. Robert Louis Stevenson is said to have thrown the first draft of "Dr. Jekyll and Mr. Hyde" into the fire. You write down your confusions, your discomforts, your exceptions, your crazy ideas. And slowly, you agglomerate improvement. You can keep improving for years. I do not believe you can think well without using an external medium [^33], something to help you improve thoughts too complex for your unaided mind. This can be a trudge, all those often tiny improvements in understanding. But it adds up and at peak moments is transformative. As the New Yorker editor William Shawn said to John McPhee: "It takes as long as it takes." And for those of us developing new creative identities, writing is one of the most powerful servants we have.