Perhaps they were witnessed to, numerous times! What do we know of regarding Hitler's upbringing?
How did God harden Pharaoh's heart? Pharaoh was undoubtedly the most "Witnessed to" person in all of history and look at what he did with it! He hardened his own heart against God's reproof which led to the events unfolding as they did.
No doubt that Hitler and Pharaoh (and Dahmer, Gacy, Pol Pot, Stalin, bin Laden, et AL) were sweet, innocent children and likely beloved of their mother or whoever! None of them will get to blame the "Environment" for which they were raised!
I could also point to the stories you have told us about yourself. Seems to me that if we were to follow the logic and wisdom of this world (that we are ultimate "products of our environment"), that you would have been perfectly justified to become an absolute monster and act out in rage because of what you have experienced! Instead, you are a testimony of God's supernatural grace and a tremendous blessing to many who know you!