Jim was once Jim Kirk, a poor farmboy on an even poorer planet, son of a man who sacrificed himself to save his new wife and newborn son from a fire that decimated their land. It would have been kinder to let them burn with him. Their life was hard, and soon after his death, Winona, Jim's mother, married again just to have someone to help around the farm. By the time Jim was 8, he wasn't Jim Kirk, and he would never be Jim Kirk again. He became Jim, the boy who was sold by his step-father to pay debts owed on the already derelict farm.
By the time he was 10, he'd been bought and sold nearly twice as many times as he had fingers and toes, and had enough scars on his young back that he firmly doubted the existence of smooth skin from the top of his shoulders to the top of his thighs. The slave brand was burned deep into tender, healing flesh, growing with him, and defining him. He managed to escape his captivity when he was 16, moving from world to world, nary a thought going to his one-time home other than to curse his father for putting his mother on that horse.
By the time he was 25, he had visited every unpopular planet in all the galaxies that could be reached, all in hopes of escaping his past. But he learned that no one can run from their pasts, no matter how far or fast they move. The mercs caught up to him on a tiny godforsaken farm planet, much like his birthplace, dragging him to the only place he couldn't escape: a no-daylight slam. He languished there for the gods know how many years, there being no way to count time down in the depths of the mine. And then a little girl, maybe a year older than he'd been when he went on the run, if that, was dropped in among the wolves. Wolves who learned very quickly that Kyra was a whole different animal from those seen before.
He and The Guy appointed themselves as her unofficial guardians, making sure that she never got into scrapes she couldn't get out of without letting her know. And Kyra flourished and grew, learning more and better ways to kill. Jim watched with puzzled amusement as she got hold of 20 menthol Kools and proceeded to try and wheedle an 'eye-shine' out of every single doctor in the prison, and then with dismay as her search and the lengths to which she would go became more desperate. And finally, after nearly a year of increasingly alarming behavior, she stopped asking the doctors, stopped soliciting the guards, and Jim breathed a sigh of minute relief.
And then there was Riddick. That was where all his problems and their solutions started. With a mad-dash to outrun the sun that led to a love that would last lifetimes.