Dreams as Bubbles
I am in a boat in the middle of the ocean going to a particular destination. For no apparent reason I'm diverted from my path and I see a shore full of people and they start shouting at me louder and louder. All of the sudden I wake up; my daughter is crying and calling me.
The interesting thing is that my daughter didn't show up crying in the boat, she affected the dream and bended the plot but the dream kept running as long as possible; its internal consistency persisted and the crying of my daughter was presented as many people yelling at me. When the consistency couldn't be maintained anymore, the dream world collapsed and I woke up.
Imagine a balloon which is being pressed gently by a finger; its surface distorts to accommodate the external pressure and maintain its structure. As the pressure increases, the surface is distorted more and more until it collapses.