Mental Training

Mental Training is a mini-game from The Legend of Zelda: Majora's Mask. Located within the Post Office in West Clock Town, Mental Training is operated by the Postman; when the Postman is not out picking up or delivering mail, he can often be found sitting on his bed in the Post Office "training". If Link approaches him, he will explain that he is imagining himself running for exactly ten seconds. He offers Link a try for two Rupees, and if Link accepts, the invisible clock starts, and Link must say when it has been exactly ten seconds. Though extremely difficult, it is possible to beat, and if Link does manage to accomplish this, he is rewarded with a Piece of Heart.

If Link wears the Bunny Hood while Mental Training, the clock does not disappear. This makes it much easier, as the player can look at the clock rather than count in their head. This is interesting because the Bunny Hood is sold to the Running Man who is the Postman's Hyrulean counterpart in The Legend of Zelda: Ocarina of Time. Though never explicitly stated, this could have been done on purpose.