Vsauce explains, or rather uncovers a lot of questions regarding consciousness. That is a state where we are aware of our self, can feel and perceive the reality form around us.
Psychology is an interesting domain and you should look to at the Leanback playlist done by Vsauce regarding consciousness. Our brain does some amazing stuff when part of the reality are not quite adding up. Seeing the Leanback answers a few questions, but raise others. Are we always conscious?