Headcanon: The Slytherin Prefects having a rough batch of first years who are crying/upset about being in Slytherin when they reach the dungeons. So they go get Professor Potter, who is not much better with crying first years, until he's honest with them. "Look I didn't want to be in Slytherin at your age either, but I can tell you I'm proud of each of these Slytherins, and I know I'll be proud of you too." The Prefects being at first annoyed, then reluctantly enjoying his frankness.
Even now, so many years later, Harry remembers what it’s like to be eleven years old. With near painful clarity, he remembers standing in the entry way to the Great Hall, listening to the nervous shuffling and whispering from the other students around him. “What house do you think you’ll be in?” “Anything but slytherin. I’ll take hufflepuff before I take slytherin.” Harry only has a basic sense of what those words mean, but he recognizes all too well the tone they’d said “slytherin” in. The same tone Uncle Vernon used when he talked about “hippies”.
When the Sorting Hat was dropped over his ears and the Great Hall disappeared, the anxiety was enough to nearly choke him. He listened to the hat whisper in his ear, saying “slytherin” like some dark promise. He’d begged at the time, anything but slytherin, anything but slytherin.
Now, sitting in front of eleven year old equally as, if not more, upset than he had been, he decided to be honest. He’d been honest with the Sorting Hat and they deserved that same level of honesty.
The Prefects had trusted him the least when he’d become their House Head. It hadn’t been easy for them to protect their younger housemates from the scorn of the other houses and even harder to fulfill their duties as Prefects when three fourths of the houses refused to listen to them half the time. What was Harry Potter, the boy who lived to defeat Voldemort, the heir to Slytherin, going to do for the young snakes crying in front of them? They’d seen no other option though, so they reluctantly marched the sniffling first years to Harry’s office and barged in the door without knocking.
“We’re just not sure what to do.”
Harry looked down at the six students in front of him, tears stained faces with red rimmed eyes. There was awe in some of them, fear in others. Harry swallowed past the nervous ball in his throat.
“Uhm, ah, everyone sit down. Prefects, you may return to the dungeons, I’ll escort them back in a little while.” They were halfway to the door when he rushed to add a, “Thank you.” They looked at him with unfathomable eyes before shrugging and disappearing out the door.
“So,” he started after a beat of awkward silence, “Tell me what’s going on?”
They all rushed to explain, tripping over their words and speaking over each other. Harry held up a hand when he’d heard enough, effectively silencing them.
“I’m going to be honest with he,” he said seriously, “I didn’t want to be in slytherin either. The only reason I was in Gryffindor was because I asked the Sorting Hat not to put me in slytherin.
He rushed to keep speaking when they started to open their mouths again, undoubtedly about to ask him if they were allowed to go ask the Sorting Hat too, “I asked for that for the wrong reasons. I thought that slytherin house was bad. I thought that it was the house for dark wizards and witches. I thought that I wouldn’t be able to make any friends because how could I be like them?”
A sense of panic overtook the first years, as if he was confirming all their darkest thoughts. Harry smiled reassuringly.
“I was wrong, though. Some of the bravest, best people I’ve known have come from slytherin house. Some of the most cowardly of men have come from gryffindor. There is no right or wrong house to be in. If the Sorting Hat thinks that you’ll succeed in slytherin, it’s because you have all the potential and traits to do so. And I’m here to help you do that.”
The first years calmed, thinking this over and staring at him with calculating eyes. One by one, they slowly nodded and wiped away tear tracks from their cheeks. Harry grinned triumphantly and stood from his desk.
“Now, why don’t we return to the common room. I’ll introduce you to some of the mermaids that like to sit by the windows.”
The walk to the dungeon was filled with excited questions and bright eyes.