There's a story here. When his mom was his age she would line up a set of matchbox cars - about 24 of them - so straight that you could put a ruler in front of them and it would touch the front tire of each. If she'd go out of the room, Bill would move one or turn it around or something. The minute she came back in she'd walk right to that one and put it where it belonged. Here, my great-grandson Jerik is lining up the plastic rings - we thought he'd just twirl them around or something - but when he finished each row was identical. Hmm. Liked the unique playground equipment at this park.