I don't journal per se, but I have a prayer journal. I agree with CC, sometimes when I look back in it it's like a different person entirely. The things I used to worry about, be fearful of, etc. aren't issues anymore. It's been a really useful tool, I recommend journaling to almost anyone. There's been a lot of healing since the beginning of my journey and I don't think I'd have been able to see that unless I could look back on the way I was.
"It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly..."