“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."” http://en.wikipedia.org/wiki/Memoir
I began this blog saying it was about nothing. That fits in with not writing a memoir because I have no memories about my life I really want to write about. I have lots of wonderful stories to tell about my family, but most of the memoirs I would write, except for the driest of facts, would be untrue.