Oh man this is kinda similar to a quirk I had as a kid. It's kinda hard to explain, but in my old neighborhood we had sidewalks like these. So if you look at the first five rows of squares starring from the bottom of the picture, you'll see that the color of the cement changes on the next row. Well the sidewalks I walked on, there would be like, 3 or 4 rows of blocks with a thicker kinda borderline between eachother. So when I would walk I would step one foot in front of the other in each block and count "one two three four, one two, one two three, one two three" etc, starting the count over every time I crossed the break or change in the cement.