Antonyms for "getting the idea" could include: confusion, misunderstanding, ignorance, incognizance, bewilderment, perplexity, dumbfoundedness, befuddlement, disorientation, and vagueness. These antonyms are all related to a lack of understanding or clarity of thought. When someone is unable to "get the idea," they may feel lost or uncertain about what is being communicated to them. It is important to be aware of these antonyms in order to recognize when someone is struggling to understand, and to take steps to clarify or simplify the message being conveyed. Communication is a two-way street, and clarity is key to effective dialogue.