Question

What is the main benefit of having the narrator begin the story with events from his childhood

Answer 1

For me, I believe that the main benefit of having the narrator begin the story with events from childhood is because when you are a child, you show more of yourself; what kind of person you are. So it would be a really good introduction of the narrator.
As you grow up, you start to face problems and get scared if you show the world who you really are because you might think nobody is going to like you or someone's going to make fun of you.
Also if you are facing hardships in your childhood, the reader would 'actually' know that and the reader's reaction might be a little different from when he/she didn't know the hardships you faced.
For example, if that narrator didn't show the childhood of the hardships he faced, and now the narrator is an adult and he gets rich and famous. The reader might think: "Ugh. How did he deserved it?"
But if the childhood is given that he faced many hardships and how he is rich and famous. The readers might think: "Aww. He deserved it!"

This is the benefits I believe. I hope this helped you <3