It's easy to keep people at an arm's length, if you've had enough practice.

Remus Lupin had a lifetime of practice.

He didn't blame anybody for it, he didn't even think about it anymore. But after years of disappointment, he knew better than to let his guard down. Invariably, inevitably, he was the one left with the deep wounds in his chest. And Lord knows he had a hard enough time as it was, without additional emotional strain. Always trying to make ends meet, only able to keep jobs for so long before people started to notice the pattern of his absences. The title "werewolf" was like a scarlet letter AND a star of David emblazoned on his chest (he kept to himself, so he read Muggle history and literature). When people found out about his "furry little problem," as James had called it, suddenly they were filled with fear and loathing. Suddenly they saw him as a dirty, dangerous Other with no morals; someone—or something to project blame onto. And who could blame them? Remus saw himself in this light as well. Sure, he was educated. Sure, he tried his very best to be balanced in his judgment of others. But he was very dangerous. He knew he could not control his monthly, bloodthirsty urges, without the help of Wolfsbane potion—and he knew very few people able to brew it.

There had been a time when he'd allowed himself to open up. He had friends, once. Looking back at his time at Hogwarts seemed like a dream now, after the loss and the betrayal that tore their little group apart forever. There, he had begun to hope. He had made plans with the boys that he considered his brothers. He trusted them—because they had won his trust. They had risked more than their lives to discover how to keep him company during the full moon, and turned what used to be the most miserable experience into something that he looked forward to, planned for, treasured. He had laughed.

Before going to Hogwarts, Remus had been a somber child. His face had worry lines on it that gave him the look of an old man, even at the age of ten. It didn't suit him. But the process of becoming a werewolf is painful, and it took a toll on him physically. He looked sickly two weeks out of the month, and as soon as he began to feel healthy, the process would begin all over again. He knew his prospects were bleak. His parents tried to prepare him for his future, as they gently told him that his "health" would not allow for formal education. Remus often felt that his parents, though loving, were often overwhelmed by the whole situation, and couldn't help feeling like a burden.

And then his acceptance letter came.

Great man, Dumbledore, Remus thought, smiling as the words reminded him of an old friend. Hagrid, gamekeeper at Hogwarts, was another who lived on the outskirts of wizard society. He'd always felt connected to Hagrid because of their marginal statuses. He admired his positivity and love of all magical creatures. I should send him and owl and find out how he's been, he said to himself. Then his thoughts shifted back to Hogwarts.

Dumbledore had made great efforts to welcome Remus to the school. The building of the Shrieking Shack, the planting of the Whomping Willow, had all been for Remus. His trust, and his belief in equal education opportunities, had given Remus the best years of his life. For the first time, Remus had friends. The worry lines slowly began to fade. He laughed often. He planned and he plotted, he played pranks like everyone else. He had always been mildly surprised and delighted that James and Sirius and Peter had accepted him into their group and cared for him like they did. So he went along with their antics, no matter how outrageous. But they were foolhardy. He couldn't count the times when they put themselves, and others, in danger, and he could no longer beg the handicaps of youth and their belief in invincibility.

His friends had offered him a buffer that he never thought was possible. Even after graduating from Hogwarts, they had plans. The four of them were going to go into business together, doing something brilliant. Magical mapping, maybe? The ideas gushed like water from a fountain. Sirius and James were so magically gifted, they could do about anything they set their mind to. Remus was the one who tempered their enthusiasm, kept them focused, and acted as the numbers guy. And Peter would come along for the ride, of course. Peter always came along for the ride. They could do anything. Surrounded by these three friends, Remus suddenly had a future. He wouldn't need to be hirable, because their business venture was going to be successful. His werewolf status couldn't keep him down.

Things seemed promising, for a while. James and Sirius came from families with deep pockets, and everyone's futures seemed bright. James married Lily at a lovely ceremony. Remus sighed, remembering the romance in the air that night as he celebrated his closest friends' love. One of the last good nights. And even then, there was a small ache in his chest. Even when the world was his oyster, with the love and support of his friends, he doubted that he could find love like that. To be so intimately close to another person, to share your deepest, darkest truths with them? Normal people might be able to hide their imperfections until after marriage—or at least until after the third date, he thought cynically. But his imperfection was so glaringly obvious. Who could accept that? Better not to even try. Better not to be hurt.

Another year passed, but things began to get darker. It became impossible to ignore the growing power of Lord Voldemort and his Death Eaters. And of course, dedicated Gryffindors that they were, the four friends decided to put their business ventures aside for the time-being, and focus full-time on the resistance. They joined the Order of the Phoenix, and fought. And grieved. And fought again.

It was strange, Remus thought to himself. Even at that time, when death was imminent, Remus was still as happy as he had been at Hogwarts. It was a grim, determined sort of happy, but he had good friends fighting by his side, and they were working together to save the world. It was exactly the sort of thing that Gryffindors are built to do: to look evil straight in the eye, and defy it, even as it looms above you, about to crash over you like a tsunami.

They fought. They grieved. They fought again.

Lily got pregnant.

Lily had a happy, bouncing baby boy. He had Lily's eyes, and James' jet-black hair.

And Remus loved that child. But there was that pang in his chest again—hidden behind his joy for his friends, and his grim, happy sense of purpose. Having a family was another man's dream, not his. It wasn't in his cards to have that kind of happiness—to watch something grow in the womb of the woman that he loves and to watch it turn in to a wriggling infant—and then see it take on his features and begin to respond to him as the baby turns into a toddler…

Remus never thought to question the loyalty of any of his friends, until it became clear that information was making its way to the Dark Lord. This was the strangest, most difficult experience of his life. He so desperately wanted to trust his friends and be trusted by them. He didn't want them to think he suspected any of them, but he also felt strained. There was a breech of trust, and yet nobody knew who had gone over to the dark side. They had been practically inseparable since the moment they walked through the halls of Hogwarts for the first time, he thought they were beyond betrayal. And yet. Something was off. He wondered if the others were feeling the same way about him. That hurt. He could expect mistrust from the whole world, but he never imagined he would lose trust from Padfoot, Prongs, and Wormtail.

And then Lily and James caught wind of a prophesy, involving little Harry. He felt them pull away from him even more. Maybe it was for the best. They had to go into hiding, and they decided to make Sirius their Secret Keeper. Questions nagged in Remus' mind—couldn't they have gone with Dumbledore instead?—and then he shushed those questions, because he would die rather than admit that he didn't trust Sirius.

And then everything went to hell. Lily dead. James dead. Peter dead. Harry orphaned. All betrayed by Sirius…? It was hard to believe, but the evidence was damning. Remus was left, suddenly alone, with the painful knowledge that James and Lily hadn't trusted him enough to keep him in the loop. They had been a tight-knit group of four, but now Remus was utterly alone. It was funny how the events of a single evening made him rethink his entire life. He knew now that he should not have trusted at all. This pain was much worse than anything before. The years of reprieve meant nothing in the end. A dull, consistent pain that comes from choosing to isolate oneself is better than the feeling of having a knife thrust into ones back by a friend. He knew that now.

So he kept his head down, for years and years. It's easy to keep people at an arm's length, if you've had enough practice. And Remus Lupin had a lifetime of practice.