Express helplessness or disappointment. The sentence "I don't understand what you want to say, after all, you are me and you are me" means that I don't understand why you want to say, after all, you are you and I am me, and we don't have much contact or intersection with each other, expressing a feeling of helplessness or disappointment, that is, when the other party wants to say something, I feel a little disappointed or helpless, because I don't know what he really wants to say or express.