At about 1am this morning while trying to sleep (I had to be up early to have a blood test done) my brain did the annoying but equally satisfying thing where it considers that to be the perfect time to have ideas. Annoying because, well, it's 1am, yet satisfying because the ideas are free, unbidden.
In the past I would probably have mulled them over for a while, hoping to remember them when I woke, but not last night. Having the notebook with me meant I could quickly scribble them down, get them out of my head, and get back to the business of sleep.
So now I have some raw material to work from and it's pretty good stuff to boot.