Actually, wether you believe or not, this is true.
Kids are happy and innocent because they "believe" everything will be allright.
For example, they just know their parents will pick them up from the kindergarden... they don't know it, but they just know... they believe they do because everytime it happends.
Then while you grow up, you are told that you have to be succesfull in order to reach happyness, you have to strive for great things in order to be happy, you have to follow a monopoli system to be a great human being, etc, because if you don't you end up homeless rotting away with maggots all over your feet.
Fact is hapiness is found while growing up in significant interactions between yourself and your caregivers; they give you, teach you things they know and that will improve your odds of survival, it strenghtens your links and gives you hope and confidence. The way we interact with people once adults is a melting pot of the way our original caregivers interacted with us when we were kids, adolescents. If your caregivers dont give you anything, you find no purpose and are frustrated, angry at those who have been loved by their parents who gave them things to continue, to be proud of, that give a meaning to their own existence.
If your parents were unhappy and had troubles interacting adequatly with you and others, this is your heritage, this is how you will interact with others once adults, imitating the things you ve learnt subconsciously.
But, at some point you become conscious, depends of people as emotional/psychological maturity is reached at different ages by most people, you look back and start understanding one or two things. But it's hard to correct them. The older you get the tougher it is. But we all do go thru that process. You either choose to do better, and give birth to offsprings that will do better with your help, or you reproduce what happened to you, knowing full well you re reproducing but unfortunately as you have no faith, no spirituality, and as nobody ever gave you hope, you just keep ruining it all for yourself and others.
Only God's words can help you at this point. There is nothing before, after, or above God, Who is, Life.
Fact is that with the new problem of overpopulation and the better understanding of how human beings can reach stable, long lasting hapiness, a selection will have to be made. Soon not everyone will be able to give birth to kids, only those who will be able to raise them so they become happy, contributing individuals. We wil reach the point where we will understand that we should not allow unhappy people to give birth to unhappy kids.
Lots of people have been able to become happy more or so even when coming from shity families, but they are excpetions that confirm the rule. How many lost souls for one genius. How many suffering human beings, for one artist, songwriter, politician, etc
And how did those who came from these shitty origins found a way to get better and help others? always by finding God himself or one of his messengers on earth.