They say puzzles are brain food or whatever, help your thinking somehow.
I think it might have to do with the unconscious processing. You know, you're trying to create a holistic picture of what's in front of you, so maybe it promotes that type of thinking that happens beneath the surface, becoming more susceptible to its clues. Well, that's my theory anyway.
Very possibly. I didn't feel I'd wasted my time with it, so that's good, I guess :)