Number 144 barking up the wrong tree. Huh? barking up the wrong tree. A very useful very practical and common idiom used in many movies. I heard it many times everywhere barking up the wrong tree. It means to be wrong about the reason or something, or the way to achieve and get something.
So, barking up the wrong tree means that you have a wrong idea, and you have the wrong reason to do something. Let me give you some examples and make it more clear for you. She thinks it'll solve the problem But I think she's barking up the wrong tree. I think she's wrong about this reason about this idea. If you think I'll help you cheat. You're definitely barking up the wrong tree.
You think you can get married to that beautiful girl? Oh man. You are barking up the wrong tree. You have completely the wrong idea.