When he was young, he did a lot of stupid things, far more than he can care to count, and he got into all sorts of trouble because of them. But he didn't really mind, never did.
He sometimes liked to bring them up to laugh about them, to Lily's amusement and James' utter horror. His best friend would try to stop him, sometimes by kicks and glares, and sometimes by pleading looks, whenever he brought up some of James' incidents before Lily became his girlfriend, but Sirius was never one to back away from anything.
Eventually, James would give up and watch as Sirius recalled all sorts of things. Remus would roll his eyes at him, but every now and then he would mention something that Sirius forgot, or laugh when James protested or threatened Sirius to cut his hair while he was asleep.
And there are things he doesn't like to think about. Things that are better left off in the back of his head, undisturbed.
But there are some thoughts and memories that are persistent, that wouldn't leave him alone no matter what. And on days like this one, with no distractions and his pride denying him to talk to anyone, there is no escape.
Sometimes it seems surreal to him, how happy he was as a teenager, and how everything collapsed in what seemed like days, although he knew it had been brewing for years.
Sometimes he wonders what he could have done to alter everything. Maybe they should have never become friends with Peter. Maybe he should have been more careful, watching the guy who seemed quiet but friendly enough. Maybe he should have gone to their house sooner.
Maybe he shouldn't have been so stupid, thinking that he and his best friends were going to make it out of this war as long as they had each other.
With a new war starting, Sirius has little time for regrets, but he still has nightmares of a broken house and two cold bodies, the sound of a baby crying echoing in his ears.
* * *
And then Remus showed up, and Sirius wanted to hug him, to apologise for being so stupid and trusting Peter without telling him, but he couldn't. He didn't have any right to expect Remus to forgive him.
His memories are a blur after then. Things happened too fast. He kept running and hiding for months. And now he is back to his old house, expected to sit down and wait, while others are in danger. He doesn't know how long he can handle the heavy silence in the house, the thoughts in his head.
* * *
In what seems like another lifetime, he was happy and carefree.
He had energetic James, whose hair was almost always ruffled. He had Remus, who was quiet and kind. He even had Peter, who at that time seemed like a good honest friend. And when he was stuck in summer with his family, trying to mute all the constant yelling and anger and hatred surrounding the place, he would sneak out late at night and meet them. They never failed to make him feel better.
The air in what was supposed to be his home was always tense, his parents constantly watching him; waiting for him to mess up. They looked at his Hogwarts cloak with disdain, scoffing at the bright red colour.
And Sirius was stubborn, a trait that he was told was passed down to him from his father. He hung Gryffindor banners all over his room. He would talk about his muggleborn and half-blood friends to his brother, who was too young then to understand their parents' hatred, who would struggle when their parents would grab his arms and pull him away from Sirius.
Regulus was different, at least for a while. Before he grew up and became the proper boy who was supposed to keep the family's legacy, the new man of the house. He became cold and distant. And Sirius should have seen it coming, but it didn't stop the bitterness and hatred from welling up inside his heart.
He couldn't care less about the family's bloody heritage and honour. He just wanted his brother back. Regulus who would stay up with him so that Sirius could tell him more about Hogwarts when he was a kid, who had a particular sparkle in his eyes that was different from the rest of their stiff aristocratic family. Not the boy they carefully constructed, the one who would shake his grip off, who wouldn't listen to him.
Sometimes Sirius wonders what would have happened if he hadn't left, or if he had convinced Regulus to come with him. Would he have listened to him that time? Would he have come with him? Would he have told their parents?
Regulus was just as stubborn as him. And Sirius was stupid. He was arrogant. After another fight with his parents, and another with Regulus, where he was trying to convince his brother that their parents were wrong, he told himself that he didn't need him, that he didn't need anyone in this family. He packed his bags and left, not giving the house a second glance.
He would never know what could have happened. If he could have saved his brothers from being a Death Eater at such a young age, if he could have prevented his death.
He could have saved him.
He should have saved him. He should have trusted Remus. He should have saved James and Lily.
Sirius has little time for regrets, but he is forced to stay in what was his home once more, avoiding certain rooms and places because it reminded him of things he would rather forget. The only things that remain from the past are his memories and thoughts, running in circles in his head, full of so many questions and what-ifs, tormenting him and driving him to the edge of insanity.