A person will usually become a shrimp-counter after having their orders mixed up at a Chinese restaurant. For example: Person A orders the Kung Pao shrimp, while Person B orders the garlic noodles. Person B decides to eat some of the shrimp, before returning to the restaurant to correct his order. Person A will then check his container of food to find that 7 or 8 shrimp are missing. Shrimp theft is a very common occurence in Hollywood.
Hal Wasserman: "So you counted the shrimp, you're a shrimp-counter now."