AN: This might be expanded on in the next couple of days, 'cause I was flooded with ideas while I was editing this. Now it's just a question of whether or not I have enough time and inspiration...
Enjoy!
He is constantly surrounded by death, but he only attends one funeral in his years of wandering. It was held three days after he awakened in the forest, but even years later, he doesn't know why he chose to attend that particular service. He had never met the teen whose funeral he attended—or if he did, he didn't remember him—but he risks the icy-cold sensation of being walked through and attends the whole thing.
There are many tears and heart-felt stories throughout, but his attention is consistently captured by two teens in particular. He is almost certain that the two are dating, and even as he watches, the red-haired boy pulls the shorter brown-haired girl to his chest, presumably murmuring words of comfort into her ear.
Maybe it's selfish to be envious of the dead, but he finds himself wishing he had friends like those, kind people who would cry over him and wonder if he was in a better place.
But it was wishful thinking at its finest, of course. The boy in the coffin was obviously well-loved if the hundreds of people in attendance were any indication, and who was there to love him if no one even realized that he existed?
(Once, still at the funeral, he thinks he sees a platinum-haired girl staring at him. But she just smiles sadly and waves in his general direction before resuming her conversation, so he dismisses the whole incident as a strange coincidence. In the years of loneliness that would follow, he would regret not talking to the strange girl. But their next encounter was decades later, when it was time to collect her soul and it was far too late.)
But maybe the envy of the dead boy ran deeper than he thought. He doesn't know when it first happened, but over the years (decades, centuries), he finds himself unconsciously using the name as his own.
(And, yeah, he'll occasionally get a sick feeling in the pit of his stomach when he finds his thoughts straying to the name's origin, but he's usually able to dismiss the feeling pretty quickly. He needed something to call himself, after all, and the dead have no use for things as trivial as names. Besides, that boy's particular name, Harry James Potter, just feels right to him somehow in a way that simple pronouns like "he" or "him" do not.
(And anyway, there's no one to judge him for it, is there?)
The blonde girl is the last one to see him for a very long time, until one day, he meets a white-haired spirit crying over the body of a (clearly frostbitten, clearly dead) child. But even as blue eyes bore holes in the back of his head, Harry says nothing to him, just collects the child's soul and leaves.
(He doesn't think he could take the disappointment if the other boy's acknowledgement of his existence was just another fluke.)