Self protection methods of the brain ((sometimes))

Its interesting, Ill know that things happened in my past, but for some reason my brain can not accept the fact that it happened at the age that it did. Its like my brain can not process the fact that these things could have happened when I was younger. I imagine it is a self defense method for the brain. To protect itself from the fact that someone had youth stolen. But why even when it  is told to me plain as day with no sugarcoating I still can not accept it. Is it because it  still  wants to cling to the notion that everything was normal? The brain protects itself in many ways, even if the methods dont make sense, it is trying to be done for the persons protection.