Comedic break:
"People do stuff. They have reasons for doing stuff; in that order." -Dave Maleckar
Human: a primate that builds a model of the universe inside its brain and upon physical maturity, moves a model of its Self inside that model; avoiding reality at all cost. (Also, see "civilization")
Emotion is how experience manifests a sense of net usefulness for each neural connection. On the macro level, we get the adaptive brain and hopefully, a sensible awareness strong enough to overcome the methods of bullies and marketers. Civilization makes people insane the same as putting a zebra in a barn without seeing the sky. Civilized human brains are models inside nesting dolls of models. It wouldn't be so bad if we didn't compete for the lowest level of usefulness to our environment (These are negative numbers under Consumerism).