Before the Games, before the reaping, before everything, Katniss was never really aware of Peeta's existence. Besides the bread incident, where he saw her at one of her weakest moments, she'd never even given the baker's son a second thought. But now, after everything they've been through, everything they've seen and heard and done, after all of the confusion and the unexpected feelings and sudden emotions, Katniss was now too aware of him.
Their return to District 12 was loud and welcoming; Katniss recalled the cheers everyone gave at welcoming home not just one, but two victors, something that had never occurred in the history of the Hunger Games. She remembered Prim's deathly tight embrace and the tears rolling down both of their faces. Seeing her sister after such a long time and after so many gruesome experiences reminded Katniss of the last time she'd seen her, of the promise she made. An elated feeling that could've lifted her into the sky took over at the realization that she kept her promise and that she was here. She had returned home to Prim and her mother, just as she had said she would.
But once all of the excitement died down, she realized how distant Peeta was being. They hadn't spoken properly since Haymitch confronted the both of them and Katniss couldn't stand how much she dreaded Peeta's absence from her life. She wasn't supposed to feel this way; it was all an act to ensure their survival. She hadn't noticed him before, so it should've been easy to let him go and ignore his existence now. To go back to how things were before. (Which was a silly notion considering everything she's been through and everything she's seen that really opened her eyes to what cruelties humans were capable of.) But it wasn't and Katniss hated this fact with such a burning passion and hated these feelings that he brought out of her that no one had managed before.
Hopes that Gale would makes her forget were crushed to a pulp when he began to get distant from her as well and Katniss couldn't help think that he was angry for the same reason that Peeta was: she had fooled them both. With Peeta she had acted out the whole thing and pretended to be in love for the entertainment of the Capitol and for the survival of them both. With Gale, she possibly led him on into believing he had some future with her, which he should've never had in the first place and should've definitely abandoned the minute she stepped in Prim's place (no before that).
She just couldn't seem to please anyone. She was too unstable and, ironically, distant. Plans for marriage and a family were things she typically avoided, but now she couldn't help but imagine a simple future with a companion for life. Children was still something she was adamant on not having for the sake of never putting them in the position she once was in and never forcing them to experience what she had to. But maybe marriage wouldn't be awful.
But of course, now she was on the opposite end of this "love" thing.
She was always aware of the boy with the bread, but he never seemed to acknowledge her anymore.