Have you ever been involved in a conversation, and you realize that the conversation to your left is actually more interesting?  So you're nodding and you're smiling, but you're really paying attention to this one over here, until you hear that last word go up, and you realize, you've been asked a question.  And you're really hoping the answer is no, because that's what you're about to say.
你有没有在聊天时， 意识到你左边那人的谈话 其实更有趣？ 嗯，你在点头，你在笑， 你一直很专心地听我讲 直到你听到我说的最后一个字音调升高， 你才意识到， 我是在问你一个问题。 然后你们希望答案是否定的。 因为那是你要说的。