A/N: Title is, again, the name of an All Time Low song. This isn't directly based on it, but I just really like the song and I can kind of find some links… Then again, my head's pretty messed up.
I do not own Harry Potter.
EDIT: Just added another little bit in here, one of those important-ish details I missed first time around P:
She was there for him at a time when no-one else was.
When Voldemort's voice whispered in his ear, when murderous images flashed through his mind at night, when the fingers of the entire wizarding world pointed at him with one word on their lips- crazy- Luna was there, reassuring him that he was just as sane as she was. Perhaps having his sanity compared to that of Luna Lovegood wasn't exactly a compliment, but it was more than anyone had given him over the past few months. She understood him like no-one else did: she knew the loss of a loved one, she knew the sight of a Thestral's muzzle, she knew what it was like to be ridiculed by anyone who crossed her path. Despite her allegedly loony ways, things made more sense around Luna than anywhere else.
When Sirius had died, when the life of the only parental figure Harry had ever known had been snuffed out, she did not pester him. She did not encourage him to talk about his feelings or weep for his memory or do anything that everyone else had tried to make him do. She just offered her sympathy, airily reminded him that they were all just standing beyond the veil, watching, whispering encouragements and skipped off to have some pudding. As he watched her go, his pity melted away and was replaced by a rush of affection; maybe she wasn't completely insane after all. And, he reflected as he walked back to the Gryffindor common room, if Thestrals and the voices behind the veil could exist (he knew they were there, he had heard them), who was to say that Nargles didn't?
A year later, when Harry had asked her to Slughorn's Christmas party out of sheer desperation, the look on her face was not one he was likely to forget any time soon. Even if she wasn't exactly what his choice of a date would have been, even if people would come to echo Peeves' cry of Potty love Loony for weeks afterward, it didn't matter. Harry knew that he had asked Luna as a friend and that she had accepted that. Even if they hadn't even spent that much time together at the party, Harry was glad he had invited her; she had clearly never been invited anywhere with anyone before, and even if she had spent the time explaining a bogus conspiracy to Professor Trelawney Harry was glad she had had the opportunity. Furthermore, she didn't carry on like Harry knew a lot of other girls would have if he had invited them. This was something he was particularly grateful for.
During his sixth and final year at Hogwarts, Luna's support remained unwavering. Her commentary at the Quidditch match had indeed been biased, but after Zacharias Smith's comments it was rather refreshing. Her lion's head hat made regular appearances and its roar was always carried throughout the stadium, nicely muting the taunting jeers of the Slytherins. And when the Death Eaters had invaded Hogwarts and Dumbledore's life hung in the balance, Luna had been one of the very few who had responded to the message through the old DA coins, proving her loyalty to Harry when he had needed it most.
When they had visited Xenophilius Lovegood on their quest to find the Hallows and Harry had caught a peek of Luna's room, Harry would proceed to never tell anyone of what he had saw. Not even Luna knew that he had seen her bedroom and the paintings of the only five friends she had ever known that covered most of it (though Harry doubted she would have been embarrassed if he did). Up until that moment he had assumed Luna was accustomed to her loneliness and that she thought nothing of it- but, then again, he had once thought Luna to be insane too. It was only when Neville told them his account of what had happened in Hogwarts since they had left that Harry realized how much the DA had really done for her. He could scarcely imagine the gratitude she must have felt towards the DA beneath her layer of dreamy indifference, and he would never forget it either.
When the Battle of Hogwarts raged around him, when Voldemort's cold-hearted, murderous thoughts pounded in his head, when Fred and Lupin and Tonks' deaths still clung heavily to his mind, when Hagrid had been swept away from him in a wave of giant, malevolent spiders, when the Dementors that surrounded him threatened to crush him in his own misery, Luna had appeared, right when he had needed her grim bravery most. Her presence by his side, her voice reminding him that all hope was not yet lost, that there were still people fighting, that the DA would always support him- that, if no-one else, she would always be there, eternally grateful- summoned what little happiness remained in him and conjured the Patronus Charm.
When Harry had, at long last, killed Voldemort, he had spent much of the morning being pushed and pulled by everyone and anyone. His tired, hungry brain struggled to keep up with the misery that they felt and the more people he half-heartedly comforted, the more he began to feel as though the people had chosen him to be some kind of God. Once again, Luna had saved the day, distracting the crowd long enough for him to slip away for some well-deserved privacy. True, Luna had lost nothing but her home during the war, but she had been brave that night, much braver than Harry would have expected her to be, and that was enough to earn anyone's respect.
Which was why, ten years later, as Harry, Ginny, three-year-old Albus and four-year-old James sat together in a ward in St. Mungo's looking lovingly down at their new baby girl, Harry felt that suggesting Luna's name for his only girl was literally the very least he could do to show his gratitude.