Writing is incredibly fun and rewarding for me. It also makes you think harder about things that you’re generally already interested in. And it gives you huge leverage: instead of trying to explain your thoughts to one or two people at a time, you do it once and potentially many thousands of people can read it. It’s also a useful resource years later to look back on, like an intellectual history of your own interests. And the more you do it, the better you get at it.