Jimmy was scared of shadows.
It had all started when he watched television. An episode of Doctor Who, specifically, where the shadows were eating people, leaving only skeletons in suits.
It was all fine and dandy for the unimaginative. But Jimmy lived in a world of imagination. And so every shadow he saw was filled with killers.
He never slept in the dark. The lights stayed on at all times. He didn’t trust the nightlight, because it only dispelled a few shadows. His parents only turned the light off for a minute, and the screaming was enough to tell them never to do that again.
Even in high school, Jimmy needed the lights on to sleep. It let him sleep through the night (so long as his father didn’t sneak in to flick off the light; that happened a few times, and the whole house woke soon after Jimmy did), but meant he also slept in class. His teachers were not very understanding.
In university, he lived on his own. He was better able to control the light. But he also had a budget, and the cost of keeping his apartment fully lit, all night long, led to his making concessions. Many concessions.
Now, Jimmy sleeps on the floor, in a small pool of light cast by a single lamp. He knows it’s irrational. But the flesh-eaters might get him, and the light wards them off.