Thinking about the structure of your personal stories is not required. But thinking about basic structure might help you identify the most effective way to write it.
Two structures you might consider are the story structure and the essay structure. Most of my personal stories are written with a story structure. However I can see how some stories might be improved if I wrote them as an essay. Other stories would be destroyed if I wrote them as an essay.
In its simplest terms, story structure is exactly like it sounds. It’s writing the ‘story’. It’s telling the story exactly like you might tell the story to a friend or family member. Think about short stories you may have read. That is what you will be writing when you use the story structure for you memoir—short stories.
When writing your memoirs using an essay structure you are writing the pieces like you would have written an essay in school. (A lot of purists will tell me that an essay is not a memoir. But if it tells your story, I am going to call it a memoir. And I am going to be happy you wrote it.) Essay structure can sometimes be a more effective means of sharing how you feel about something as opposed to sharing an event or happening.
It does not matter which method you use; as long as it conveys the message or story that you want to share.