To answer the question, I will pose a question of my own. Why in dreams do we go along with it? Why do we not question the fact that we are dreaming, when dreaming? The dream, even regular dreams we only remember, is reality to the mind. We always except the situation we find ourselves in, and go along with it. Like in one of my recent dreams, my room's door lead to a beach, and I never once questioned on how that was possible. That is the answer, because to the mind, dreams are real!