I've always been amazed how the various people in my dreams have 'things to say' in real time. The dialog is created at that instant, obviously my conscience is providing the words they say - just amazes me. Sometimes it goes awry though, during a dream today I motioned for someone who wanted to talk to me to come over ... after a few meaningful words she started talking gibberish and I then woke up. I guess I didn't have anything 'scripted' for her, and the result was gibberish. I tend to think that's why I wake up from most dreams - they degenerate into nonsense and that 'shocks' me into awakening.