Harry's POV
Harry was sure he made peace with it, that the last 12 years were enough to vanish the fear that came with that idea, but he was wrong, as the shape of Harry's fear came to light he had to admit this still terrified him.
The shape of the fear wasn't a monster, nor was it a real person, hell, it wasn't even one fear, it was two combined.
His fear has the shape of a boy with a book in his hands.
The book was named 'Harry Peverel and the boy who lived' with a painting of himself fighting against Marcus, and as much as the idea of him being a story scared him, that everything he works for, everything he does, is meaningless, it was the words that came from the person who held the book that shook him to his core.
The boy looked to be in the same age Harry was, yet small and skinny. He had untidy black hair, bright green eyes, a thin face and he wears round eyeglasses.
Yet the thing that was dominating his face was the lightning bolt-shaped scar on his forehead.
Yes, it was the original Harry Potter, the one that died the moment he came to this world.
"You know it's your fault, right?" The shapeshifter said, having an angry look on his face "you killed me the day you were born, and If you didn't, they would have lived! Hell! All you needed to do was to stay at the Dursleys's house and they would have survived!" The angry look on the accuser's face changed into pity. "And for what? The good ending was already known, why try and change it? Why try at all? It's not like any of that is real!"
The laughter came naturally, with no need of any help or spell, as he finally understood how the Boggarts choose the shape to which they change.
They don't go after your greatest fears, nor do they go after the first to come into your mind.
Boggarts go after the biggest irrational fears, the one that you know doesn't matter, or silly, but no matter what would always be there, haunting you.
Neville's irrational fear of Snape was overpowers by the fear of being unable to live to his parents imaginary expectations, whether because of the few words Harry said before, the gift in first year, or something else, something made this irrational fear to become his strongest inner demon.
Lupin fear of the moon make no sense, shouldn't he be scared from something else? Werewolfs? Hurting someone? People finding out he was a beast? But the irrationality of this fear is what made the Boggart change to that form.
Was anything real? Maybe it was, maybe it wasn't. But, did it truly matter?
Maybe he was truly a character in a story, maybe the story was written by a character in a movie, which was filmed by someone in a dream.
Did his old life which he didn't remember even matters?
No, they didn't.
He lives in this world, he affects the people of this world, and if this world is just a story? It wouldn't change a thing for him.
As for his parents? While it was true that they might have lived if he wasn't a part of their life, by agreeing with the idea that he was at fault he disrespect their memory.
They had their own mind, they made their own choices, and the only one at fault for their death is the murderer and those who helped him.
He could keep explaining to himself all of it, but it wouldn't matter.
The fear of being nothing, the fear of knowing you are the cause of his parents death wasn't something he could stop himself from fearing.
So why did he laugh?
Because it was at that moment, when the face of the original Harry Potter told him that he killed him, that if he followed the scripted he would have got the happy ending as it was supposed to be, that he truly realized he doesn't care for canon, he didn't want the happy ending, nor did he want to follow the scripted, and even if he thought about it before, even if he thought he understood, for the first time he felt free, like he can truly change the future.
It was that feeling that made that laugh come out, that made the Boggart retreat to the wardrobe, and that made him resolute about his future choices.
Remus's POV
Remus wasn't sure what just happened.
The Boggart changed to a smaller size of the boy, who looked much more similar to Marcus except skinnier, and told him how everything was his fault, and how he killed the skinny version of himself. (Remus was seriously confused on that part.)
What Remus was sure about, was that he needed to tell about this to Dumbledore, and as soon as possible.
The turning of Harry's body toward him caused Remus to blink his thoughts away as he smiled at the boy.
"Are you okey? Do you need chocolate?"
"Yes, thank you." The boy replied quietly.
As he turned away, he barely noticed the boy pointing the wand toward him, and he didn't have the time to exclaim about the boy doing wordless magic before the red light smashed toward his body and he passed out.
Harry's POV
While he felt guilty about it, Harry couldn't let anyone find out any of his secrets, especially not someone who is the Potter's and Dumbledore's little bitch.
So it was only after a quick stupefy, a little longer obliviate, and a really long confuding, that Harry felt safe enough to leave the classroom, not forgetting to cast a 'notice me not charm' on himself on the way out.
As he walked out noticing the paintings, he couldn't help but curse himself for not putting the charm in himself on the way in, as he is about to have a long, confuding day....