One of his five favorite books where insane characters come to be taken for or treated as normal,as shared at Tor.com:
Emmanuel Carrere, The MustacheRead about the other entries on the list.
A simple plot. A man who has always worn a mustache shaves it off, planning to surprise his wife. But when he reveals his shaved face, she isn’t surprised at all. She says, “But you never had a mustache.” At first, he thinks she’s joking, but slowly it becomes clear to him that he’s the only one to remember he had a mustache. Her non-response to what he sees as a dramatic change in his appearance ends up threatening his own sanity…