Harry Potter was an unusual child. He would argue that he grew up in unusual circumstances and that he was normal for those conditions. Harry spent his childhood observing, copying, and learning. It was through a series of events that he learned the rules.
His cousin Dudley screamed and threw a tantrum when he wasn't given the toy that he wanted. This resulted in him receiving two toys from Aunt Petunia. Harry didn't receive any dinner. He screamed and threw a tantrum. The result was twenty lashes from his Uncle's belt and the lack of food for a week.
Rule 1. Not everybody is equal. Equal actions do not cause equal reactions.
Harry brought home his first report card, full of little plus marks and check marks to show that he was excelling in everything they had done. He was promptly beaten and yelled at for daring to show up their precious Duddykins by cheating and using his freakishness to make his cousin fail. Harry brought his second report card home, full of minuses and empty boxes to show that he failed on nearly everything they had done. He was promptly beaten for being a lazy no good freak that was reflecting poorly on his wonderful and generous Aunt and Uncle. After that he always achieved the best marks he could achieve and accepted the beatings as a given.
Rule 2. There is no correct solution, only the one with the least amount of negatives.
Harry ran across the playground, trying to escape Dudley and his gang before they could grab him and use him as their own personal punching bag. He was not fast enough. By time he was able to pull himself off the ground and limp his way to class he was late. When the teacher yelled at him he tried to explain that he was attacked by his cousin and the other boys. Dudley explained to his teacher, and later to his father, that while they were innocently playing Harry tried to attack them but when they dodged Harry fell to the ground, resulting in his injuries. Harry received two punishments that day, one from his teacher for being a liar and one from his Uncle.
Rule 3. The truth is arbitrary. Truth or lie does not matter, only what the other person perceives to be right matters.
Aunt Petunia had the neighbor ladies over for tea so they could all gossip together. When Harry came inside after finishing his outdoor chores with several bruises showing on his arms and a black eye the ladies were quite shocked and concerned. Petunia was quick to tell them about her problem nephew who always got into fights with kids on the street. How the boy's parents were drunkards. The only reason she left out the usual line about his whore of a mother was because she did not want them thinking too bad of her through association. She then went on about how they took the boy in and did their best for him despite him following after his parents. How she was at her wits end on how to correct the boy of his degenerate lifestyle. By the end all the women were comforting Petunia while shooting dirty glares in the direction the boy had gone. A part of them was ashamed that they for an instant thought that there was something bad going on in this house when Petunia was so kind and generous to take in her nephew despite him being a problem child.
Rule 4. A beautiful lie is far more believable than the ugly truth.
All of these rules accumulated into what he considered his golden rules of life.
Do not trust adults. They do not care. They will not help, especially if you are not their own child.
Pain is as much a fact of life as breathing. There is no point in trying to fight it. No point in trying to escape. Both will only lead to greater pain.
Then, there was the most important rule.
Words are useless. They lead to pain and suffering. Do. Not. Speak.