Slanging It Around

Sometimes, people use slang but they only know the denotation of the word-- so that the phrase works logically and grammatically-- but when they are told the connotation or the root of the slang, they are shocked by what the phrase actually refers to (e.g. on the first day of school, one of the younger teachers was taking a picture of another teacher for the yearbook, and when she got the photo just right, she said, "that's the money shot!" and we told her that she absolutely could never yell that phrase again in school, and then we told her why; at first she didn't believe us, and said that must be something from "your generation" but once enough unsolicited people gave her the same definition, she realized that though the literal definition of "money shot" was a memorable or impressive picture or image, there was no way to divorce the literal meaning from the derivation of the word).