I would like to know if there is an idiom or a proverb in English to denote a situation in which one watches a play or a dramatic performance without knowing its story. It is similar to participating in a discussion and opining in it without having much idea about the incident on which the discussion is in progress.
I would use the expression in a context like: "I don't know really what happened earlier, who said it, to whom and what exactly. So, my interference is (like)......"