Your Past Doesn't Define Who You Are
\[Couldn't figure out a way to word that correctly so I hope you get the point\]:
Examples are:
Orihime Inoue – (Bleach) – Her parents were very abusive, her mother was a prostitute and her father was a drunk, she was beaten as an infant to stop her crying so her brother would be the one who'd actually take care of her, eventually her brother ran away with her and raised her by himself for years until he got hit by a car and after she dragged him to the nearest hospital he needed to be transferred due to the facility having just opened only for him to die mid ambulance ride. She was now on her own and constantly bullied. But she turned out being a very kind person who couldn't stand to see anyone getting hurt and is a very loving mother and wife.
"Big" Jack Horner – (Puss In Boots: The Last Wish) – A quote from the man himself "You know, I never had much as a kid. Just loving parents, stability, and a mansion... and a thriving baked goods enterprise for me to inherit. Useless crap like that." Despite having a pretty nice upbringing he turned into an evil, selfish, irredeemable crime boss who wants all the magic in the world for himself... Why? because he got shown up by Pinocchio and hates his lack of magical abilities. He collects baby unicorn horns to use as ammunition, tries to shoot a puppy in the face, sacrifices his loyal henchmen for his own benefit when there were definitely a better way and is just a jackass. He's very entertaining as a villain.