Customers aren't always right, but they're happy to be confidently wrong. This person worked at an ice cream parlor as a teenager, which is a typical first job for many kids. U/chsser writes that they generally enjoyed the role, but they had a few regulars who had zero patience. At any restaurant, there are bound to be delays, and you might even get the wrong order from time to time. If you're a regular, it'll probably happen to you eventually. The person antagonizing this teen was a regular to…