In the early stages of a panic fear takes over. A fear from not knowing much, of anything, for sure. The more information we have regarding a thing, the less fearful we become.
It comes from being huddled together in the dark, not seeing what happens just beyond the tree line. Once fire illuminated the shadows we were able to conquer those fears.
But as we are the ancestors of those early fire-starters, so too are our fears ancestors of those early shadows. It is important to light the night, and shine upon the unknown, to diminish our fears.