I wrote a book in my dream last night. Well, I didn't complete it, but I started it. It had a beginning and I knew how I wanted it to end. It had a cast of characters and I had written vivid descriptions of each of them - 10 total. I was super excited and couldn't believe how easily it was coming together. The plot had something to do with a plane crash. I remember being concerned that people would compare it to Lost, but there was nothing supernatural about it.
I woke up in the middle of the night and thought, wow, I should write all that down. At that moment, I still remembered all the details. But, of course, I just went back to sleep and woke up this morning with just the recollection of the dream, but not all the details.
I remember an interview with Paul McCartney where he said he wrote "Yesterday" after dreaming the melody. Maybe when these dreams happen, I need to get up immediately while it is still fresh and transcribe them. Maybe my own "Yesterday" is hidden deep in my subconscious somewhere.