 Could have mentioned that sooner, but it would have been less dramatic. Mr. Rubik's Cube has since become one of the most recognized puzzles on the planet, which billions of people have tried their hands at, including David Calvo of Spain, who approaches the task with his own particular panache. From our archives, here's Mr. Calvo telling former As It Happens host Carol Off all about it. David, I've seen the video of what you do. It's quite amazing. Maybe you could describe what it is that you're doing there.