Harry was often stunned how much he and Ginny had fit. He supposed it was the like the Muggle jigsaw puzzles Dudley got when he was little before Aunt Petunia had discovered that Dudley didn't have the patience for them. They fit in a way was instinctively right. Their relationship had always been full of fire, and passion. They'd lived with the end of the world snapping at their heels, threatening to overcome them with each step.
Harry guessed he shouldn't have been so been so surprised when it finally had. He knew he shouldn't have cried so hard, staring into her dull brown eyes, remembering how bright they used to be. Harry's heart was frozen, and felt like something was missing all the time. He supposed he then knew what a jigsaw puzzle with a missing piece felt like.
Harry could not pin down the exact moment when he had stopped spending every moment pining after the shining, vivid red-haired girl he'd given four years of his life to. It was undoubtedly around the time that he'd noticed Luna had matured. It took him a while to notice that she'd stopped quoting The Quibbler to him, understanding that he didn't want to hear that all of the war could have been avoided if they had just appointed a house elf as the Minister of Magic. He knew she still believed it, and at times he caught her opening her mouth as if to say something, but closing it rather decisively. When asking her one day to go ahead and say it, Luna had told him unflinchingly that she would rather not, as they would just argue.
So it was surprising, and not, when she was the first person to show up at Grimmauld Place when Ron and Hermione went missing. She'd brought all her stuff and moved in after a month, when it seemed the silence and loneliness of the place threatened to strangle Harry while he was sleeping.
His love for Luna had grown while he wasn't paying attention. It was not a sudden, burst of love like he had felt for Ginny, but a slow gradual love. He hadn't even been paying attention to whenever he'd absent-mindedly brushed a stray hair away from her face, or begun to smile when he was with her. It was then that he understood that he was in love with Luna. Luna seemed to know already, and when he kissed her one day at breakfast, she'd told him that it had taken him long enough; she was beginning to think he had Loser's Lurgy like Zacharias Smith did.
It was strange, being with Luna. It was calming and peaceful. Opposite than what he and Ginny had shared. And sometimes he missed Ginny. He missed the way her hair felt when he ran his fingers through her hair, and the exasperated look she would always give him whenever he'd said something utterly stupid. But mostly, he missed the way she fit.
But he and Luna also fit. It was a different sort of fit, however, one more cautious and slow. He and Luna had relationship based on understanding. Luna had always understood Harry, and Harry was starting to understand her. He began to understand that everything that Luna said made sense, even if it was odd or unlikely. He began to understand that maybe, just maybe, the beautiful blond-haired woman staying by him, would help move on from the red-haired girl that had enveloped his live for so long.