Think of your dreams like being in a video game. In first person view, you're seeing everything as you would in real life, through your eyes. In third person view you're just looking at everything from a different perspective. In other words, you can still press the B button to jump, you just see it differently. OBEs generally imply not being able to control your body, with the feeling that your mind or soul is leaving your physical self. So in an OBE, you can no longer hit the B button and see your character jump. Get it?