A Finger for the Past
Jackson had a troubled youth. Not only did he face relentless bullying for his gender and sexuality, but he was also heavily bullied due to his quirk. Jackson was born with an entirely useless quirk as far as hero work was concerned- the ability to change the color of his eyes. That's it. He might as well have been quirkless, though he found he was unwanted among the quirkless, too. Around his teen years, Jackson had enough. He fought back as if his life depended on it and suddenly he wasn't pathetic anymore- now he was "crazy". According to everyone else, he had to be crazy to try to take on bullies with actual quirks while he only had fists and rage. Jackson didn't care anymore. They could call him crazy, they could push him and punch him and throw him to the ground- he was going to come back up swinging, even if it killed him.
Years later, after a stint in juvie and a lot of equine therapy, Jackson remembers the angry kid he used to be. He remembers the mistakes he made, but he also remembers everything he learned along the way. Fighting until his bones broke didn't bring him peace. Giant animals that could break him in half but chose kindness instead brought him peace.