Says James Somers:
You should write because when you know that you’re going to write, it changes the way you live. I’m thinking about a book I read called Field Notes on Science & Nature, a collection of essays by scientists about their notes. It’s hard to imagine a more tedious concept — a book of essays about notes? — but in execution it was wonderful. What it teaches you, over and over again, is that the difference between you and a zoologist or you and a botanist is that the botanist, when she looks at a flower, has a question in mind. She’s trying to generate questions. For her the flower is the locus of many mental threads, some nascent, some spanning her career. Her field notebook is not some convenient way to store lifeless data to be presented in lifeless papers so that other scientists can replicate some dull experiment; it’s the site of a collision between a mind and a world.
More interesting insight:
When I have a piece of writing in mind, what I have, in fact, is a mental bucket: an attractor for and generator of thought. It’s like a thematic gravity well, a magnet for what would otherwise be a mess of iron filings. I’ll read books differently and listen differently in conversations. In particular I’ll remember everything better; everything will mean more to me. That’s because everything I perceive will unconsciously engage on its way in with the substance of my preoccupation. A preoccupation, in that sense, is a hell of a useful thing for a mind.