Although he was married briefly, and many years later his former wife was moved to state, peculiarly, that he was an “adequately excellent lover,” it is clear from all available evidence that sexuality, procreation, and the human body itself were among the things that scared him the most.
He was also frightened of invertebrates, marine life in general, temperatures below freezing, fat people, people of other races, race-mixing, slums, percussion instruments, caves, cellars, old age, great expanses of time, monumental architecture, non-Euclidean geometry, deserts, oceans, rats, dogs, the New England countryside, New York City, fungi and molds, viscous substances, medical experiments, dreams, brittle textures, gelatinous textures, the color gray, plant life of diverse sorts, memory lapses, old books, heredity, mists, gases, whistling, whispering—the things that did not frighten him would probably make a shorter list…. The things that did not scare him generally are absent from his work.
Yeah, horror writers usually scare easily, that's where their ideas come from.
For example, Stephan King is afraid of cars among other things, that's where Christine and Maximum Overdrive comes from. (Ironically, he also almost died being struck by a car. I doubt that alleviated his fear.)
cars are a bafflingly rare fear honestly, they're 3-ton vehicles that regularly whoosh past people at high speeds and have no actual mechanism to prevent being driven by drunk people other than them not wanting to risk being arrested
Misery was about his drug addiction. Drugs were the superfan. They're always there to celebrate your victories and always there to rip you to shreds at a moment's notice.
Ah well. non-euclidean geometry was kind of their quantum physics: a super fancy and mysterious scientific thing that intrigued everyone but only few understood.