The ideal choice for puzzle addicts everywhere, Mind Trainer Toilet Roll is toilet paper with a variety of mind stretching quizzes and problems. It's so efficient to double up on functionality, don't you think?
Each sheet of paper has a puzzle on it to keep your mind alert and ready for action, and so you won't be too frustrated, the answers are printed too, upside down. Mark yourself honestly and keep a score sheet in there too, so other members of the household can marvel at the improvement in your mental agility.
Or just keep the whole thing as a private entertainment for yourself. The choice is yours.