The opening of your personal narrative helps your audience to understand the personal journey you've taken and why it is important. While there aren't any hardline rules for writing your introductory passage, there are a few guidelines you can follow to make sure your story will be structured logically, that you engage your readers and that they trust your mastery as a storyteller.
Start En Medias Res
While you may be tempted to begin your story with a philosophical generalization or some other form of direct address to your readers, the most effective way to captivate your audience and to immerse them within the world of your story is to begin with a scene. You don't have to open at the beginning of a scene either. You can start right in the middle. For example, if you're writing about your lifelong passion for the game of baseball and you want to open with the scene of the first game in which you played, you could start at the moment your bat connected with the ball and became your first hit.
Pick a Poignant Scene
Your opening scene is critical because it establishes expectations in the minds of your readers. As they read it, their brains are trying to make assumptions about what the book will be about, who the main character is and what the major conflict will be. So choose a scene that helps your audience accurately determine these answers. If your story is about your struggle to protect your siblings from an abusive parent, even as adults, start with a scene in which you protect them when you are children. Starting with such a scene will establish a logical trajectory for your conflict as well as your theme.
Play with Structure
Just because it's a story about your life, however, you don't have to start at the beginning. You could easily begin at any point in the story, as long as it makes sense to do so. For example, in the narrative about protecting your siblings you could alternatively choose to open with an encounter between you and your siblings as adults, one that illustrates the personal journeys you've taken, and then advance the narrative by flashing back and recounting your struggles. This technique is often called book-ending, because it is common to return to that later scene -- or time period -- at the end of the story. In this way, the opening and closing serve as narrative bookends for the story.
Make it Interesting
Aside from being logical and establishing the thematic drive of the story, your opening has to perform the additional job of hooking your readers and whetting their appetites so much that they feel compelled to keep reading. For example, Lucy Grealy opens her memoir, "Autobiography of a Face," with the exact moment she collides with a child on the playground and hurts her jaw. That injury immediately exposes a deadly cancer -- and resulting facial deformity -- that sets her remarkable struggle in motion and alters the trajectory of her entire life. Whenever possible, open with a scene that drives the tension through the roof and makes your readers feel as though they need to find out what happens next.