The best thing about journaling or blogging, aside from clearing your head, is to reflect on previous posts. Some of my old posts are so ridiculous, I can't believe I even wrote them! I think it's neat to see the full spectrum of thoughts and emotions that I'm going through at various times. It shows resiliency that I didn't know I had!
I've journaled since I was a teenager. My personal journal is rated "R", of course, but when I die, it's free for the reading. I think my kids will value the journals that I keep for them and will learn a lot from mine. What better way to really get to know a person's innermost thoughts??