Everybody makes mistakes. No one is right all the time. Everyone has something wrong with them. Everyone has a terrible and wicked secret with which they live. Everyone, stripped to the bare essentials, is out for themselves and will cut anyone's throat and walk away from anyone in trouble if doing so means a little less trouble for themselves.
All humans are but a gene or two removed from the primordial slime.
People are no good. No one does anything for anyone. Parents prey on children. Children prey on parents. People live like beasts of prey, predator or victim, and then they die.