I found out that when I blog about something I am learning, I am retaining a lot more information about whatever I am writing about. I mean, it's not even close. I wrote something on my blog about streams in NodeJS a few months ago, and even if I barely used them since them, I remember a lot more about streams than things I use way more frequently.
Teaching is the best way to learn as they say. Well, when you write about what you learn, you have to express your ideas in words. It's very different from just thinking you 'got it'.
So yeah, this is the main thing I found out thanks to blogging, I just remember things a lot better.
Totally agree Damien. Learn, code, learn, write, teach, learn...learn... etc! Great for information retention, and great to move from unconsciously incompetent through to consciously competent.