I finally noticed the error - it was 12-18-18 NOT 12-12- 18

Here is the spread with 12-18-18 as the inspiration.. I originally wrote the numbers large with markers that have a silver edge. After I'd finished the background with the text ( twelve eighteen eighteen written with different tools, in different directions but a similar font all over,)I didn't like the numerals. I cut them out of a piece of paper with a practice mandala on it and pasted them over the pink ones.

As I started the table of contents, I came across another spread with the numbers as the image, they were similar.   It was 11-7-18. The paper is a watercolor folder, cut in half .