Harry Potter knew very few truths during his childhood.
The first was that darkness meant safety. Darkness meant that he was in his cupboard and he could, once the light under the doorway disappeared, steal food. Darkness meant that the others in Dudley's gang (Malcolm, Dennis, and Piers) would have to head home. Darkness meant that the adult Dursley's would leave Harry alone, preferring to ignore his existence.
The second truth was that Harry always, always fought back. The odds of escaping didn't matter - even with four boys against him he could put up a good fight once they caught him. Harry simply couldn't allow himself to be still, to let them beat him without defending himself. The few times he had, he was certain that he would be meeting his parents soon.
Fighting his uncle's large, one-handed chokehold was harder, especially when Harry was small and weak from not being fed, but Harry still hit and kicked and made it so that the physical lectures were the last resort punishment.
The only person Harry could not fight back against was his aunt - and that was not for lack of trying. All his blows seemed to miss, and even the one time he tried to bite her she didn't appear to feel it. The plus side was his aunt couldn't hurt him directly either. Only she was the adult, so she found alternatives: forcibly scrubbing him in the bathtub, hitting him with whatever she was holding at the time, and, of course, instructing Dudley to hurt him when she felt Harry deserved it.
Harry truly earned his reputation as the neighborhood delinquent. No one ever noticed that he was never the one who instigated the fight, or maybe no one else cared. His skin and his self-preservation skills marked him as violent, as dangerous.
And then there was his least favorite day of the year: Halloween. Because, although his aunt typically spent more time washing Harry's private parts than anywhere else, Halloween was the only day of the year that Aunt Petunia could have his body pinned to her mattress to do what she liked with. Uncle Vernon always took Dudley out trick-or-treating, and Harry was completely alone.
Aunt Petunia always kept the lights on - little decorative lamps strewn about the bedroom. She wouldn't let Harry close his eyes. Halloween was the only day Aunt Petunia willingly mentioned her sister. She'd tell Harry what a freak his mother was as she raped him. She'd talk about her jealousy, about how Lily always had everything she wanted but "I've taken your child now! You may have been the pretty, magical daughter with the perfect man, but now you're dead! You're dead and your son is mine! Mine mine mine. And he's so helpless and small, just like I was."
Darkness meant safety from his relatives, safety from dysfunctional family relationships and the awful, awful implications of what his aunt said and did. Safety from violence in all its forms.
The day Harry was rescued was a dark day. Harry spent most of it staring out the window as his uncle drove to escape the letters. The letters for him that took away his dark little cupboard and moved him upstairs with four locks on his door. A black sky, a miserable family.
And an eleven year old boy counting down the seconds until a giant breaks down the door, reveals the hidden secret of why the Dursleys hated Harry so damn much, and feeds Harry his first birthday cake in nine years.
Harry followed the Rules with the giant: don't ask questions, show no ignorance, and follow instructions. He'd faltered at first - revealing he knew nothing about the world, asking about the wizard money - but he didn't need to defend himself at all on the trip. (Which was good, because Hagrid could crush him like a toothpick or permanently disfigure him like he had Dudley.)
Harry was thrilled to finally meet someone who knew his parents, knew and liked them! The stories were almost better than the magic, during the trip anyway.
Harry hated all the bright lights of Diagon Alley, but the sheer magic of the whole place meant he could tell where he was going even as his eyes remained unfocused the whole trip. Harry couldn't show his distaste, not in a world where he's famous!
The boy at the robe shop reminded Harry far too much of one of Dudley's friends, but otherwise the wizards and witches were all amazing! And the bank had actual dragons! Harry talked to some snakes at the pet store and surreptitiously bought a ball python when Hagrid was checking out all the beast equipment he needed to buy before school started again.
The snake kept Harry company, which was good, because Harry spent most of August locked back up in his cupboard. His trunk had been miniaturized so his relatives couldn't burn it. Harry read by the light of the hallway and discussed the new materials with the snake. She, the yet-to-be-named snake, had lived her entire life in the pet store, and had overheard all sorts of information about Hogwarts and wizardry.
The snake allowed Harry to name her, and the day before Harry was to leave he found a name in his history textbook: Hedwig.
The day Harry left, Hedwig shrunk herself to fit his miniature trunk. "You'll be able to make friends with people who might be biased against Slytherin... besides, I want to know where Vanished Objects go!" Harry didn't exactly have a choice, so he reluctantly accepted his first friend would be traveling with his possessions. He unlocked the cupboard and began walking. The train station was only a few miles.
A regretful few miles later, Harry discovered that the platform required running headfirst into a wall! The family of redheads helped him with his nerves, and his unshrunken luggage.
Harry had grabbed the most interesting textbook for the train ride: Defensive Magic For Beginners. He began reading about the differences between a jinx, a hex, and a curse.
A few minutes after the train had begun moving, Harry saw one of the redheads open the compartment door. "May I sit here? Everywhere else's full."
Harry nodded, and the boy entered, carrying his pet rat with him. Harry was immediately grateful Hedwig had decided to stay in her terrarium - she'd eat the pet of a potential friend! Harry took care to ensure the boy wasn't sitting too close - Dudley ingrained that instinct into him.
The boy introduced himself, and soon the two were chatting. Harry kept Ron focused on his family to escape any questions about Harry's, which wasn't hard. Ron enjoyed talking about his brothers, and especially their skill at Quidditch, which Harry knew nothing about. Harry bought snacks.
Unfortunately, the boy from the robe shop made a rude introduction towards the end of the ride. Harry restrained himself from defending his friend physically, reminding himself he wanted a good reputation here so maybe they'd believe him about the Dursley's and he wouldn't have to return. His sarcastic smile and comment on the "right sort" did the trick, anyway.
The trek to the castle involved much shoving and pushing past the older years. Harry hated it - hated being touched, especially by accident when he had no reason for being angry about it. Ron assumed Harry's anger was about Malfoy, and explained the blood feud between the two families to Harry.
The Great Hall was far too bright. Too bright too loud too much - Harry wanted to hide underneath a table. He was relieved when the Sorting process came to him because he could hide under it.
"Interesting," the Hat began, speaking in Parseltongue as that was the language Harry's thoughts were in. "Yes, Hogwarts isn't exactly a closet, child, but your eyes will adjust. Now, you certainly are brave. Yes, and wise beyond your years - a nice thirst to prove yourself as well... Do you have any preferences?"
Harry hadn't been paying attention to Malfoy's sorting, to preoccupied with the overload of stimuli, but the thought of spending an entire year watching his back, without even his bed being safe, constantly on guard, was miserable. Not with Malfoy, please, Harry thought. The hat chuckled, "So polite, young one. Oh, you've had it beaten into you, but your chivalry is still a virtue. Better be GRYFFINDOR!"
Thunderousapplause erupted. Harry ran to the table. Ron soon followed.
Harry had taken to keeping his wand between his legs or sitting on it. That way, he technically had a reason to constantly keep his hands by his bits. The other students probably would not attack him, but Harry preferred safe to sorry. The habit went unnoticed by other people.
Soon Harry stopped, keeping his wand in his robes. He began to feel safer, the only place he remained fully on guard for was Potions. The professor hated him. Harry was happier than he could ever remember being.
And then Halloween came.