Harry Potter was sitting in a filthy pub in muggle London, drinking enough beer to render himself near unconscious. He wasn't meant to be in the pub, he was meant to be at a wedding. Ginny Weasley's wedding. Ginny Weasley's wedding to Draco bloody Malfoy.
Harry Potter was sitting in a pub and drinking huge quantities of beer, trying to forget how stupid he was. After all, it could have been his wedding to Ginny Weasley. She'd been infatuated with him for years. She'd accidentally put her elbow in her butter dish the first time she'd seen him, and she wrote him a singing valentine during her first year at school. He'd saved her life a few months later, which the ungrateful wench seemed to have forgotten, in her glee over marrying Draco Malfoy, the world's biggest prat.
Hermione had told him that Ginny had been desperately hoping that he, Harry, would invite her to the Yule Ball her third year, but back then he had been infatuated with Cho Chang, with her foreign beauty, and the allure of an older woman. He never even glanced at his best mate's little sister. He had always seen her as nothing more than the girl next-door. He really should have listened to Mrs. Weasley's tales of how the girl next-door usually wound up being your soul mate.
But he hadn't. Nor had he listened to Hermione when she told him what an amazing girl Ginny was the next year. At that point, he saw her as a friend, someone to joke with, and someone to help him on his missions to rescue the people he loved, whether they were really in danger or not. In the back of his mind, Harry realized that she was coming along because of her feelings for him, but he brushed them off, seeing as he hardly returned them.
But the next summer, the summer before her fifth year, and his sixth, Ginny Weasley had gone through a transformation. Where mere months earlier she had been stick-like, she developed curves to make any girl jealous. Where once she had been a tag-along to the golden trio, she developed an independent streak, and came into herself. Not long ago, she had been absolutely dependent upon other's approval; suddenly she didn't seem to care anymore. She had always been smart, but she became absolutely passionate about her studies, and her future. She found her calling in teaching, when Harry had quit doing the DA, Ginny took it over. She decided that she wanted to be a Defense teacher when she graduated. During her fourth year, Ginny Weasley had been Harry's replacement on the Quidditch team after Umbridge banned him, and she'd been brilliant, but now she tried out for chaser, and made the team, and was perhaps the most brilliant chaser Hogwarts had ever seen. She became a member of the order at the same time as Harry, Ron, and Hermione, at fifteen becoming the youngest ever full order member.
Harry began to fall in love with Ginny Weasley at around the same time as every other male at Hogwarts, and at around the same time as she outgrew her childish crush on him.
As Harry started to watch her more, he noticed things he never had before. For example, she was friends with his mortal enemy, Draco Malfoy, had been for over a year. She was perhaps the only Gryffindor Snape liked, being an expert at potions without being the least bit know-at-all-y. She volunteered in the Hospital Wing twice a week, and was actually an expert mediwitch. Her favorite food was pumpkin soup, which she had to have at least three times a week if she wanted to stay in good humor. Though she was famous for her bat boogey hex, it was just one of the many hexes she was an expert at.
He asked her out around midyear, just before the holidays. He didn't really expect her to say yes, she had been turning boys down right and left, and seemed to be waiting for that special someone to come along and sweep her off her feet. So he wasn't all that surprised when she said no. But he kept asking, and finally, around mid-January, she said yes. He was only temporarily ecstatic. It soon became evident that she had accepted only to make someone else jealous. What really irked him was that the someone else in question was Malfoy. She was constantly bringing him along when she hung out with him, and he overheard her admitting to Luna that she felt really bad for stringing "poor Harry" along, but if anyone would make Draco jealous, it was the boy-who-lived. "Besides," she said "he strung me along all last year. So I guess it's like some kind of karma."
His pride and self-respect told him to end it with her then, but he convinced himself that if she stayed with him long enough, she would come around and fall back in love with him.
She ultimately did wind up breaking it off with him in early March, and a week later showed up as Draco Malfoy's girlfriend. He soon learned that Malfoy had had a crush on Gin since third year, but had been too cowardly to admit it. He wanted to tell Ginny that this meant that their friendship had really been a farce, that it was all a ploy to get in her pants, but Hermione had gotten gist of his thoughts and banned him from even talking to Ginny about her new boyfriend. She didn't, however, forbid him from throwing a few hexes at the prat.
The prat proposed to Ginny that summer, on her birthday. She said yes.
A week later they got their Hogwarts letters, and Gin found out that due to her exemplary test scores, and the extra work she'd been doing after class (Harry had no idea about this, but she had apparently confided in Malfoy about it), she was being promoted to seventh year. Harry saw this as little more than further proof of how brilliant the witch he'd been stupid enough to turn down really was. She must have been the brightest witch of her age, even Hermione never skipped a year.
The same batch of letters informed Malfoy that he was to be head boy.
Mrs. Weasley, who Harry had always seen a something of a mother, had betrayed him by throwing the happy couple a party. The party was in honor of Ginny's promotion, Malfoy's head-boy-ship, and their engagement. Harry had then proceeded to get drunk.
Still he had hoped that they would break up, realize that they were not right for each other, for a while.
The final battle had come that November. Both Ginny and Malfoy had fought hard, as had Harry. Ginny wound up going into a coma. Afterwards, Malfoy never left her bedside, watching her with tenderness in his eyes that Harry had never thought possible in a Malfoy. When Gin finally woke up, he was there, and he was the first thing she saw, and she gazed up at him with a look of pure love and adoration. That was when Harry knew it was over. And, when he got drunk enough, Harry was able to be happy for Ginny, happy that she had found her happily ever after.
Now, just over a year later, Ginny was finally walking down the aisle, towards her soul mate, and Harry was sitting in a filthy pub in muggle London, hoping to drink enough beer to forget about her, but how could he possibly forget about the one girl he would ever truly love? And he could never forget that if he hadn't been such a prat back in school, she could have been his.