From TAKE THE MONEY AND RUN:
Allen (a bank robber), walks up to the teller and hands her a note that reads. "I have a gun. Give me all your cash."
The teller, however, is puzzled, because he reads "I have a gub." "No, it's gun", Allen says.
"Looks like 'gub' to me," the teller says, then asks another teller to help him read the note, then another, and finally everyone is arguing over what the note means.
Allen does not succeed in robbing the bank because he is the only one who defines the situation as a robbery.