Why write a dream diary?

I have a dream diary. I used it in my first creative writing assignment and I got a pretty decent grade (yay!). Aside from that, I don't really show it off to people other than to brag "oh my gosh, I had this dream last night and you..."

As a writer, I think my dreams are important. They're basically my uncontrolled imagination taking me on a ride. The story is usually engaging, the characters realistic and well-rounded (I once had a dream where I was married for two years to a dream character and didn't question it). This isn't to say I could make stories directly from my dreams - I couldn't. Not tangible, linear ones that made sense anyway. But they are good for a few things:

• Keeping my imagination on its toes. Naturally.
• Forcing me to write as soon as I wake up in the morning. Then, even if I don't work on my story or do some poetry during the day, I have at least written something and haven't lost touch with the practice.
• Even if the dream makes no sense, there could be an aspect of it that's really interesting, or a character who is a force of nature and can't be forgotten. Once they're written down, they're there for me to come back to at a later time (hopefully after I've at least eaten breakfast) to expand on.
• I remember my dreams far more when I'm in the habit of writing them down. This means I get to annoy my friends have interesting conversations with people I know about them, as well as giving me the dream-strength of mind to lucid dream. And that's everyone's secret goal, right?

Do you keep a dream diary? Why?