Every food worker has that one Karen story that they love to tell. While working in fast food service, employees are bound to encounter crabby customers daily. Customers show up at their hungriest, ready to eat ASAP. They often won't bother being polite to the employees, and if their food takes more than a minute or two, they'll start loudly complaining to everyone in earshot about it. Other people will get their food, but insist it just “isn't quite right.” Maybe they insist their fries are co…