As a literary genre, a memoir (from the French: mémoire from the Latin memoria, meaning "memory", or a reminiscence), forms a subclass of autobiography – although the terms 'memoir' and 'autobiography' are almost interchangeable in modern parlance. Memoir is autobiographical writing, but not all autobiographical writing follows the criteria for memoir.Memoirs are structured differently from formal autobiographies which tend to encompass the writer's entire life span, focusing on the development of his/her personality. The chronological scope of memoir is determined by the work's context and is therefore more focused and flexible than the traditional arc of birth to childhood to old age as found in an autobiography.Memoirs tended to be written by politicians or people in court society, later joined by military leaders and businessmen, and often dealt exclusively with the writer's careers rather than their private life. Historically, memoirs have dealt with public matters, rather than personal. Many older memoirs contain little or no information about the writer, and are almost entirely concerned with other people. Modern expectations have changed this, even for heads of government. Like most autobiographies, memoirs are generally written from the first person point of view.Gore Vidal, in his own memoir Palimpsest, gave a personal definition: "a memoir is how one remembers one's own life, while an autobiography is history, requiring research, dates, facts double-checked." It is more about what can be gleaned from a section of one's life than about the outcome of the life as a whole.Humorist Will Rogers put it a little more pithily: "Memoirs means when you put down the good things you ought to have done and leave out the bad ones you did do."