The fallacy of personal incredulity occurs when one finds a concept difficult to understand, or simply does not fathom how it works, then they conclude believe that it is likely untrue.
Irene was 89 years old, had never left the small town in Iowa where she was raised, and she had never seen a vessel. Though Michael had tried to describe what Navy life on the submarine would be like, she didn’t believe a word was true. How could a glorified metal tube sustain the lives of many men, while submerged for months at a time?