For you stated objective of finding yourself, reminiscing about your past in depth would only be pointless if you plan on doing nothing with the information or plan on using it to excuse current behavior. Each person does come into the world with some personality. Ask any parent of more than one child. This means, even if the children are born of the same parents and raised the same way, they will react differently (in most cases) to the same experiences. If you are just trying to understand how or why you behave certain ways, recalling your childhood can help you figure it out. Now, IMHO, this can be helpful in just understanding yourself, but the more productive thing to do would be try to use that information to better yourself. Some of our childhood experiences cause really good personality traits others cause problems. An example, my mother had a bad temper while I was growing up. You never knew what was going to set her off; each day it could be something else. I found myself later in life reacting the same way, and questioned it because I am not an angry person. Once I realized I was reacting the same way she did, it was easier to change (mainly, because I did not want to raise my children in the state of fear I was raised in.) No, there was no physical abuse. It was state of fear because I never knew if I was going to do something “wrong”.
You mentioned 9th grade. Most people begin to question themselves and those in authority around that time. This is one of the reasons most parents have difficulty with teenagers. They begin to develop a sense of themselves and the world which is independent of their parents. They can ultimately accept or reject all or part of the values their parents raised them to believe in up to that point. Their personality and values are no longer just an extension of their parents.