When your dominant arm is more buff than your non dominant due to the effect of oftenlymasturbating.
Man: "I swear, my left arm is strong, but it doesn't look like it compared to my right."
Man 2: "How often do you beat the meat? Sounds like a case of Muscle Jerkitis."
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.