Tim Ferris had a great podcast with Daniel Pink a couple weeks ago. I'm a big Daniel Pink fan. I highly recommend reading his book To Sell Is Human.
In the podcast, Daniel talks about the fact that one of the main reasons he writes is not to teach people something but rather for him to learn something. And often, when he sits down to write about an idea part of the way into it he realizes that the idea stinks. Or that the theory he set out to write about is just wrong.
This really resonated with me. The reason I've kept writing on this blog for more than ten years isn't to tell people things I know that they don't (though if that happens that's great). The primary reason is that I learn through writing more than other medium. If I have an idea or a theory I find it enormously valuable to get it down on paper. I'm no different than Daniel in that I have literally dozens of draft blog posts in my Squarespace account that I haven't published because halfway through writing them I realized the idea wasn't good or was wrong or wasn't fully baked.
I highly recommend that people write down their ideas on a blog or an Evernote or a personal journal. Writing forces you to focus and think clearly and consider alternatives and ensure that an idea isn't just a whim but a well thought out, actionable concept that matters. The clarity that comes from writing is invaluable.
For me, that clarity has been the best thing about writing on this blog.