The Game

http://en.wikipedia.org/wiki/The_Game_%28mind_game%29
The Game is a mental game where the objective is to avoid thinking about The Game itself. Thinking about The Game constitutes a loss, which, according to the rules of The Game, must be announced each time it occurs. It is impossible to win most versions of The Game; players can only attempt to avoid losing for as long as they possibly can. The Game has been variously described as pointless and infuriating, or as challenging and fun to play. As of 2010, The Game is played by millions worldwide
Rules
There are three commonly reported rules to The Game:
1. Everyone in the world is playing The Game. (Sometimes narrowed to: “Everybody in the world who knows about The Game is playing The Game”, or alternatively, “You are always playing The Game.”) A person cannot not play The Game; it does not require consent to play and one can never stop playing.
2. Whenever one thinks about The Game, one loses.
3. Losses must be announced to at least one person (either by using a statement such as “I Lost The Game” or by alternative means).
The common rules do not define a point at which The Game ends. However, one reported variation states that The Game ends when the Prime Minister of the United Kingdom announces on television that “The Game is up.” After you have announced your loss, some variants allow for a grace period, during which you cannot lose the game, which varies in time. Note, however, that the grace period is not part of the three documented rules.
Strategies
Some players have developed strategies for making other people lose, such as saying “The Game” out loud, or writing about The Game on a hidden note, in graffiti in public places, or on banknotes.