Mockingjay spoilers. Review please! Thanks!
She never understood it. She heard him rant and yell and complain every other day, out in the solitude and safety of the woods, but she brushed it off as pointless anger. It would never make a difference. It would never matter. There would never be anything anyone could do about it. He didn't have any particular reason to hate the Capitol, just the same generic motivation to rebel as everyone else; they made life hard, they killed people without a second thought, they had everything while those in the Districts had nothing.
But he did have a reason. Because they could take her away. Because of how selfish those bubbly, glitter-painted people were, she had to take out tesserae and was put in that bowl four times a year. Screw the fact that he had six. Every year those glass orbs were set on the makeshift stage, he saw the slips in the girl's container and all he could think is that they were hers. Any of those slips, all of them even, could be hers, and she could be taken away from him in an instant. Maybe forever.
And then it happened, and it hit him like a train, one of the thousand-miles-per-hour ones that would take her to the shining city in a matter of hours. The Capitol, with their cruel Games, took her away. Forever. Prim's name was drawn, and then she volunteered. There was no going back. No fixing the damage that had been done. She was gone.
When she came back to the District, she was no longer alive. She was surviving, barely holding on, but in no way was she living. They didn't talk much, even on the days he wasn't down in the mines. And he threw himself more than he ever had into the hope that the country would become fed up and rebel. That he could get back at the terrible place that not only took his precious Catnip away, but threw her into the arms of another boy, rubbing it in his face, leaving him with nothing to do about it.
Just when he thought maybe she was finally coming back, becoming the girl he once knew again, they took her. Again. They managed to have she and Peeta arranged to be married, big and public, and any hope he had regained disappeared. No, not all of it. But the few little bits and pieces of wishes he had left were taken away when they took her the third time. This was when she would die. She was going back into the Games, supposedly carrying a child, with no one who could protect her this time. Wouldn't that make a story? The pregnant girl on fire and the other star-crossed lover, only one of which would make it out this time. The audience would love that.
Then when he got her back again, saw her broken and crumbled, all he wanted to do was put her back together. They built up his hope again, but the moment she came back to the world it was crushed. Again. She didn't care about him, not in comparison to Peeta anyway. They took him, the last thing she felt she could count on (though he was right there, right there to take care of her) and he watched her already wrecked state fracture even further. No matter how hard he tried, there was nothing he could do.
So he stopped. He stopped trying. He pushed her to the back of his mind. She was a goner. There was nothing he could do to bring her back to him. So he would make sure that the people who did this to her, to him, to everyone who had to watch her change, would pay. Nothing mattered more to him (except her). He fought. He worked. He concentrated and focused. And the entire time he was fighting beside her, he got to see the girl he loved again, if only for a few days. He saw Catnip. He saw the raw determination that he'd known, the compassion and even the fear. So he brought her back to his consciousness, and he tried again.
He was just doing his job. It was war, it was necessary to kill people. There were victims on both sides; it was something one just had to deal with. So he worked with Beetee and they made the bomb, the bomb that could win the war for them. The one that won the war.
If he knew victory would be the thing to cut that last string, that last thin thread that kept her with him, he would've never done it.
He never said goodbye. The last time he really talked to Katniss Everdeen, to his Catnip, was before the 74th Games. But she didn't know how much he cared about her. She didn't quite know everything about him yet. So it didn't count.
Maybe he never had her. Maybe after everything she had gone through before she knew him, there was no one left to have. Just the ghost of a person that could act like her, could talk like her (could sing like her, it killed him), but wasn't the girl he loved. Maybe he never really knew her.
Maybe she was always gone.