The hat has seen many a things. Many a things that have brought him joy and amusement. Like when he searched through Neville Longbottoms memories and saw one where he was crying because he got cake in his hair as a toddler.
He seen many a things that have brought him sadness and despair like when he searched through Barty Crouch Jrs memories a long long time ago and spotted him losing his best friend at eight for not being good enough.
There are rarely things that have ever broughten hat to feel pain or humane emotions such as anger. They only happened rarely in his lifetime until Harry Potter had been Brought up to his stool and Hat was placed on the boys head.
Hat used to tell Dumbledore everything, Hat did. He used to tell Dumbledore what was happening to his students in their lives before they had come to Hogwarts to be sorted. He used to sing out songs about the joyous times and curl his withering lips into a sneer while explaining the abuse some went through.
Hat told Dumbledore everything and Dumbledore listened, but he never did anything and Hat couldn't do anything. He was a Hat and soon enough after the incident with Regulus Arcturus Black Hat soon went quiet about the past of his students. Dumbledore would ask questions but he would never answer just sing his new first year song for the next students to arrive.
Hat used to think Dumbledore was the greatest wizard of his time after his incident with Grindelwald. He used to belive Dumbledore had truly gone good but to allow his students to wallow in pain and misery for their years was something Hat wouldn't ever stand for again. He hated Dumbledore because it seemed that he never left the dark side.
It seemed as though Dumbledore was only dressing up his words and knew the true value of undying trust and faith and used it. Hat hated him because nobody would believe this silly old Hat who was as crazy as Voldemort himself.
Nobody believed Hat but McGonagall and that's why she was his confidant when she was around. He told her things, everything he'd never to tell Dumbledore. Because McGonagall didn't seem to trust Dumbledores judgment either.
So here Hat sat, on a stool as he sung his song for the new rounds of students wondering and wondering what life would be like if he could tell the truth.
Hat sat on Ronald Weasleys head and laughed as he shook then blurted Gryffindor and laughed again as he relaxed. He sat upon Neville longbottoms head and fought with the boy about where he belonged. Gryffindor of Hufflepuff. He went to gryffindor begrudgingly that boy and Hat was irritated by the time they ended their little spew because nobody seemed to be as stubborn as that two left footed boy.
He sat upon Hermione Grangers head and smiled so wide that his stitches had probably broken. Her life was great but much like how Muggle students seem to struggle with the concept of Wizard money and he laughed while shouting Gryffindor.
Hat barely touched Draco Malfoys head, all he needed to know was the name of that boy, no need to look through his memories he was no doubt a Slytherin. But Hat had barely skimmed through his memories and shouted Slytherin. He felt bad because maybe The boy was like his mother. They all had bad lives and Hat felt like he should have at least looked.
Then Harry Potter sat and Hat went through his memories and Hat had felt the anger he had never had before. His memories although nonmagical were full of things he'd not want to see. Hat knew what Lily Potter had written in her will with James Potter. He was there when Dumbledore went through them at his desk while Hat was pretending to be asleep.
Hat hated Dumbledore for allowing a child like this to experience things worse than being witness to his parents death so young. Hat hated Dumbledore for not helping Sirius Black when Dumbledore knew the truth. Sirius Black was the first student Hat Had who was a Black and went against everything they stood for. Hat Liked Sirius Black he was the student Hat took the most pity on because he experienced so much torture for his brother. Hat watched his memories and had no doubt that he'd be the greatest pureblood Gryffindor in all of Hogwarts History who was raised and bred from pureblood who beloved themselves and fought to be the best.
Hat hated Dumbledore for ignoring all the signs Hat knew he saw and proceeded to sacrificed those Hat knew could have lived.
Harry wanted to go into Gryffindor but Hat hated Dumbledore. Hat normally took all of the students wants into consideration. He normally always did and Hat never let himself be persuaded by his own inhumane emotions. But Dumbledore would be expecting Harry in Gryffindor and what better way to ruin his plans than Put Harry Potter in a house Dumbledore dispised and was more than biased towards because more dark wizards came out of than good.
So Hat with all his rage bottled up opened his mouth and shouted into the silence:
"Traitor!"
And if nobody understood what he meant other than professor McGonagall than let it be known that Hat doesn't care. Harry Potter never got sorted. Harry Potter wasn't allowed back to Hogwarts until Hat was deemed sane enough to sort him.
Harry Potter was sent abroad to Dumbstrang. There, he was sorted into a House meant for the cunning and Hat couldn't have been prouder of himself. Because atleast there he would learn how to stand for himself. He wouldn't have to fight the evils Hogwarts held for him here that Dumbledore tried to allow.
Then forth year came along and Harry Potter was requested to Be sorted. Dumbledore went against school policies to do this underwraps but Hat sat on Harry's head and relished In the life he now saw Harry Potter had. Living with his Godfather Sirius Black for a full year. His life before a better picture where they were afraid of Harry. Hat didn't feel bad he made his decision and Harry Potter was better than ever. He was a happy student and Hat would never change his mind ever again.
Hat and Harry Potter parted ways when Hat refused to sort him and instead shouted out:
"Better!" This time. Harry Potter gave him an odd look but Hat winked at him when Dumbledores back was turned and it seemed Harry Potter didn't get it.
So Hat lived his life, singing for the new first years and relishing in the way that Voldemort had yet to return. Hat found the utmost pleasure in Dumbledores frazzled state when he was shuffling through his things and muttering to himself.
McGonagall seemed proud of Hat too.
Hat watched as Dumbledores life seemed to crumble in front of him and he was banned from teaching at Hogwarts due to the actions he'd taken on young students from his first day as Headmaster that were hidden from light. He watched as Professor McGonagall took the man's place with a bright smile and appointed new rules. And indulged in every students needs. Watched as she approved and congratulated multi-house relationships. Watched as she made sure all of her students were comfortable and made sure she was strict enough to seem it but not enough to not seem like the person one could go to when they were in need.
Hat didn't see Harry Potter or Sirius Black until a young boy named James Arcturus Malfoy-Potter was in his halls and awaiting his sorting. Harry Potter was at the head table sitting in the spot for defense against the dark arts and sitting right beside him in the newly appointed potions seat was Draco Malfoy.
Hat shouted out Slytherin upon the cunningness he spotted in the happy memories of the young boy in front of him. Hat saw Harry Potter enter into the newly appointed Headmistress McGonagalls office the next day with both the young boy James and the Man whom he'd seemed to have married. Hat also noticed that Sirius Black was approved to meet him because he was there as well holding hands with Little James as he sat him on his shoulders.
Harry smiled at McGonagall nodded his head and gestured to Hat. McGonagall allowed Hat to sit on Harry Potters head once more and Hat laughed as he sorted through Memories. The life Harry Potter had was significantly different from the life Dumbledore had planned for the boy.
Harry seemed to have befriended Draco Malfoy during the triwizard Tournament. They both bonded over Viktor Krum being the Champion. It seemed as though Harry Potter and Draco Malfoy had fallen in love somewhere around sixth year, just three years after Harry had proved his godfathers innocents by trapping Peter Pettigrew.
Harry Potter seemed to have lived a normal life with his Godfather and the only thing that seemed to go according to Dumbledores agenda was when Harry found out about Horcruxes and destroyed everyone including himself.
Hat felt his nonexistent heart break watching the young Harry Potter sob to his Godfather and family friends and Draco Malfoy before igniting fiendfyre in the fields of Malfoy Manor.
Harry Potter seemed to have survived by miracles and Hat smiled as he watched the last remaining piece of Voldemort turn to dust.
Harry soon later took Hat off and held him in hands with a smile pointed at Hat. Hat smiled back as Harry sat him on the stool.
"I should thank you. You did me wonders by not sorting me Hat." Hat tipped his top down.
"Harry Potter has no idea what Hat has seen in his life. Hat will continue to help everyone in anyway he can. But Hat couldn't let Dumbledore ruin another life and sit by on a shelf to watch it happen." Harry nodded his smile tensing breifly on Dumbledores name.
"So what House would he have really been in had you allowed it to go on?" Sirius Black questions curiously
"Gryffindor of course."
"And what House would he have really belonged in?" Little James asks.
and Hat smiles widely with the black holes of his eyes crinkling with old age.
"Slytherin My boy."