Memoir/Personal Narrative
A memoir or a personal narrative is a personal story about the author's life. It is non-fiction, though it may use hyperbole. It usually includes some analysis of the situation that the author was able to do with the benefit of hindsight.
A memoir focuses on one specific event or situation. It relies on sensory language and common themes/situations in order to connect with the reader in a meaningful way.
When people say they are going to write their memoirs, they usually pluralize the word because they're going to write about more than a single event or situation.
Some notes on writing a memoir/personal narrative
A checklist for writing a memoir/personal narrative