I just had a flashback today to an early childhood memory when I saw one of these toys. You know, the one with the different shapes where you put the holes in the blocks that fit. Well I used to have one of these. I'd worked out which holes the blocks went in of course and only considered that this was worthwhile doing once I had finished with the toy. What delighted me was trying to find new and creative ways to get the blocks to "almost" fit. Much like the blue cube in the picture above.
I remember when I'd come up with a particularly interesting combination I would proudly show my father who would look at me with a worried smile.
He was probably thinking "the boy's an idiot".