3. Become a chess genius without touching a chess board
How: By playing chess in his imagination, an ordinary man programmed his brain to develop the skills he needed to beat a Grandmaster, even when he had no one else to play against.
The science: Anatoly Sharansky, accused of being a spy, spent nine years in a Soviet prison, often stuck in solitary. To avoid going insane, he played mental chess, imagining moving both the white and black pieces, because he had very bizarre ideas about how to not lose his mind.
It sounds like a waste of time, since the mental effort required to remember where each imaginary piece was would be too great to make the process productive. Also, when you're playing against yourself, the competition is pretty consistent.