Right
The Sorting Hat had been right, in that Harry would have fallen apart had he had a female Head of House. What the Sorting Hat forgot, however, was that reminders of the past do not always come in authoritative packaging. Harry was reminded of his Aunt in other ways, ways harder to avoid.
Luckily for Harry, Ravenclaw and Hufflepuff had many classes together, meaning Harry could reconnect with Ron and learn magic with a known friend. In the classes without Hufflepuff, Harry partnered with Anothony Goldstein or Terry Boot, but he couldn't tell if the boys actually liked working with him, or were just partnering out of convenience or - as was often the case in primary school- as a way to get more information to take the piss out of him with later.
But all classes have two houses in them, at least. The first year class was simply too small not to. And while Dumbledore took pleasure in scheduling joint Gryffindor-Slytherin blocks, leaving Ravenclaw with Hufflepuff, the schedule did mix up a bit. The few classes where Ravenclaw was not with Hufflepuff, it was with Gryffindor.
Harry had no problem with most of the Gryffindors. Seamus Finnigan's penchant for setting himself on fire was humorous, a virtue not often found among the far-less-accident-prone Ravenclaws. Neville Longbottom, too, commiserated with Harry over both being despised by the Potions Master, albeit in different classes. (Professor Sprout paired them up in Herbology, and it's hard not to talk while planting) But the Gryffindor girls, there was a problem there.
Her name was Hermione Granger. She was the one with her nose in the air when it wasn't in a book, looking down at the other Gryffindors as she corrected their spell work. She was bossy, and a tattletale, and she looked at everyone with an air of disdain, as though she knew she was better but was too polite to say so outright. She corrected Harry's Herbology work physically, by grabbing the shovel out of his hands and shrieking at him and Neville, who apologized the way preteen boys do when they aren't actually sorry.
In short, she reminded Harry far too much of another woman who corrected his gardening, who looked down on others, who had that same look in her eyes that Harry came to associate with discomforts of various sorts. She reminded him of Aunt Petunia.
Harry knew he was being ridiculous, that she was just an eleven year old girl with no friends, but he couldn't stop the flashbacks when she had grabbed him in Herbology. He couldn't stop himself from dissociating sometimes when he accidentally caught her gaze, his mind stuck on another gaze watching him as he dressed, watching him and touching him and "into your cupboard, no food for two days! You freakish devil, bewitching me with temptation!" He couldn't stop himself from flinching, from choosing to not browse areas of the library she was in. He couldn't control it, his feelings about her, and so he hated himself for them. He tried to suppress them, as he did every emotion from Back Then. He failed at every attempt.