Someone does not need that at all.; That's the last straw! (Always sarcastic. The someone can be a person's name or a pronoun.) Jane: The dog died and the basement is just starting to flood. Fred: That's all we need. Sally: Bill, the check you wrote to the Internal Revenue Service was returned. There's no more money in the bank. Bill: That's all we need. Bob: On top of having too many bills to pay, now I have car trouble! Mary: That's just what you need!