I heard a very funny cheder story.
In williamsburg a caretaker from the Satmar cheyder asked some 10 or 12 yr old boys “How can I say in Yiddish GOOD MORNING to the rabbi?”
So the boys told him “Ich bin a putz”.
So the next day they are all sitting in class learning and the caretaker/janitor comes along with his mop in the hall, outside the classroom door and gives a big smile and waves to the Rebbe calling out “ICH BIN A PUTZ”
The rebbe knew the boys were behind this.