In late December 2017 i was unable to sleep one night, I don't remember why. As it is often when you’re between being asleep and awake, an idea struck me. I think everyone has experienced this. Unfortunately when we don't write it down, it's gone the next morning. I got back up and sat at my desk and put the idea on a piece of paper.
Then I went back to sleep. When I woke up the next morning I found this on my desk.