This is my journal. It amazes me that a little book of paper could be so important to me. Its a huge part of my life and I usually have it with me wherever I go. I have kept a journal since I was 12 or 13. That's when I feel like my life started to get complicated and the only thing I could do was write about it. Writing helps me sort out my thoughts in a way that makes sense to me. Most of the time there are so many things going on in my head that its difficult to think clearly. Journaling calms me and forces me to focus. I get lost in the writing. I can (and do) write in my journal for hours sometimes. Just a stream of consciousness about whatever is on my mind that day.
I also put keepsakes in it. Its full of ticket stubs, pictures, matchbook covers...anything that reminds me of something special that happened that day. There have even been times when I didn't have my journal with me and felt like writing so I just grabbed a napkin, scrap paper, whatever was available and wrote on that. Those little pieces of my thoughts are taped into the pages of this book. I'll flip through my old journals sometimes just to see where I was at that time in my life. Its interesting to see how I have grown and changed over the years.
If you don't keep a journal, I highly recommend that you at least try it. Let me know how it goes.