consciousness
More it requires a brain
Being conscious is being awake and aware
Consciousness seems a puzzle to some along the lines of "How can a mostly water organ contemplate the Universe?"
My 2 cents, being conscious is being awake and aware, having consciousness is being awake and aware that YOU ARE awake and aware and circling around "How am I doing it?"
Once it clicks you are only a collection of chemicals engaged in a very complex activity (thinking about thinking) the goal is to work out HOW the process began
Onto the stage comes religion, which informs the masses "We KNOW"
Of course they don't, but they spin a good story
Religion, plague on humanity, unfortunately giving unverified stories for years