Recently I've been working late into the night, which has reminded me of a moment I had while finishing the art for The Secret Plan.
I was up late working and didn't realize that I had used up all the sheets of paper on the pad that I'd been painting on. I went ahead and started another picture... on the white cardboard backing of the empty pad.
The texture seemed different and the painting kept looking funny but it still took me a little while to realize what I had done. And in the morning I found that I had left myself a note so I wouldn't forget the benefits of sleep.