I Baffi by Emmanuel Carrère

In this psychological thriller, the protagonist experiences a surreal and unsettling transformation when he decides to shave off his mustache, only to find that no one around him acknowledges the change. As he grapples with the bizarre reactions of his friends and family, who insist he never had a mustache, he spirals into a world of paranoia and self-doubt. The narrative delves into themes of identity, perception, and the fragile nature of reality, leaving readers questioning the boundaries between sanity and madness.