There is no threshold that makes us greater than the sum of our parts, no inflection point that at which we become fully alive. We can't define consciousness because it doesn't exist. Humans fancy that there is something special about the way we perceive the world and yet we live in loops as tight and as closed as the hosts do, seldom questioning our choices, content for the most part, to be told what to do next.
I think human consciousness is a tragic misstep in evolution. We became too self-aware. Nature created an aspect of nature separate from itself. We are creatures that should not exist by natural law... We are things that labor under the illusion of having a self, that accretion of sensory experience and feelings, programmed with total assurance that we are each somebody, when in fact everybody's nobody...