An animalistic response to stimuli that threatens one's existence. A deeply seeded emotion that bubbles to the surface in the face of a threat or the unknown.
It could be argued that our entire existence is thanks to fear.
But then, that would be acknowledging that fear makes it okay to ostracise others, to kill, to wage war, to commit genocide.
That, in the tens of thousands of years that it's taken humans to evolve into what we are today, we are no different than what we were.
That, while the passage of time and mutation has changed our appearance, deep down in the core, we are no different to our distant ancestors.
No, we are no different. We live with fear, are controlled by it, and we die with it.