A pool of fresh water is special. It's special as it’s a bit like our consciousness. If you try hard you may be able to see really little waves or ripples in the water. They’re really slight. The surface of the water is like the surface of your consciousness. The part that you're cognizant of. When it ripples - when it's interacting with the world around you it’s obvious and you’ll get ripples. The surface ripples are what you're commonly aware of.
When you think, hear, speak, cry out, engage in something physical or stressful the waves are produced. With meditation that all stops. Your brain may be totally still, unmoving. It’s really possible. When the surface of the brain quiets and becomes still we begin to see and feel what is underneath. We wouldn’t know there's anything much underneath our consciousness except what we may see from the surface.