The Paradox of Child Happiness

I used to believe disparities created unhappiness but travelling around the world, I kept noticing a counter-intuitive phenomenon over and over again:

No matter where you go, the happiest children will always be found in poverty and children born into privilege are invariably miserable, anxious and lonely.

As I was trying (failing) to buy happiness at the time, I became obsessed with figuring out the seemingly illogical nature of child happiness. I think I get it now; it's a function of (perceived) debts owed.

Children are happy in poverty because the world doesn't owe them anything. They're carefree as no one cares enough to make them suffer to please, keep up appearances, behave themselves, live up to expectations or reach their full potential. There's no obligation or pressure; in poverty they have nothing to lose so they live without fear. 

Unlike the children of privilege, slum kids are happy because they're more or less free. 

If my theory is correct, the way to ensure misery would be to lean on children to make them conform to some ostensible standard of successful behaviour, leading them to believe they're then entitled to what the world will never owe them. Make them suffer to please you and they'll spend their lives in angst, fuming at perceived insults and injustices, keeping markers, threatening payback, at war with a world they imagine is disrespecting them when the truth is, no one could possibly care. As the unpaid 'debts' mount, they'll be overwhelmed. Misery and conflict will be all they know. 

Elliot Rodger was led to believe he was entitled to what the world would never owe him. Someone misled him.

To ensure happiness, you'd simply tell children the truth: The world owes them nothing. They're not entitled to anything from their fellow humans. Life is what they choose to make of it. There is no fairness, justice or equality; any they receive is just a bonus. If allowed to respect themselves and treat themselves Right, children won't grow up imagining the world owes them unpaid debts, leaving them free to have fun instead.