One theme that repeats is that of being very high up over ground, usually in some rickety vehicle or lifting device which I'm barely able to control.

The other thematic element which I can't understand is that I'm often 'surprised' in my dreams. How does that happen? That a mind is able to trigger a surprised reaction on itself. The obvious answer is that the unconscious is pulling one over on the conscious, but does that mean that one sleeps and the other does not? Or they sleep different?