This one comes straight out of the book 'Tools of Titans' from Tim Ferris.
He interviewed Jane McConigal. Maybe you've never heard of her, yet she's pretty famous in the gaming world apparently. (we didn't know her either, don't worry).
She has written a New York besteller called: 'Reality is Broken. Why games makes us better, and how they can change the world'. Hell yeah! And she's pretty famous for several TED talks about games and gaming.
Anyway, what is this Tetris thing about?
Recent research shows that games like Tetris, Bejeweled or Candy Crush can help overwrite negative visualisation. It also helps with preventing PTSD. And, in case of Jane, it helps with insomnia.
Why? Because of the strong visual, problem-solving characteristics of these games. You see 'visual flashbacks' (like blocks falling or pieces swapping). These occupy the visual processing center of your brain.
And that's why you can't focus on other obsessions or cravings. (this works for overeating or other addictions as well). This effect lasts for about 3 to 4 hours.
So Jane does 10 minutes of Tetris every night, to fall asleep.
Next time anyone says gaming is a waste of time... You know what to say. It's just therapy.