I have always though memoirs were a way to appease a famous person's ego. I mean, what makes you think that your  life was so interesting that people will want to read about it. Memoirs are coming out of the woodwork and most of them are actually ghost authored... don't ask me how I know.

The memoir game works when a person wants their story told their way. There are biographies out there written by people who may not have even consulted the person the biography is about. These are called unauthorized and are made up of accounts from people in the person's life, but not the person.

Memoirs can be about anyone that has an interested story to tell. They contact an a ghostwriter and this person sits down and begins to chronicle this person's life. It's made up of their thoughts and ideas about the things that have happened in their life. Often, this stuff isn't verifiable or a downright lie, but since it comes from the person it gets written down.

I could write a memoir and say JFK told me all about the plot to kill him and since there isn't really anyone to back it up or refute it stays in. Writing a memoir is definitely not journalism. A memoir is also not a biography.

A biography is a chronicle of the events of a person's life. A memoir is their life in their own words and often includes commentary about people, places and events that a biographer wouldn't bother with.