u/SoullessDCLXVI: Reverse Dursley living situation. Petunia and Vernon love magic and are psyched to know that it's real. They genuinely love the Potters and mourn them as is natural. Harry, on the other hand, believes it to be a fiction and can't stand it. He doesn't despise his Aunt or Uncle, but he is known to get into heated fights with them about living in fantasy lands.
Not a wizard, not for you
"You think this is going to change anything?" Harry ripped the letter in half and threw it in the air. Though it pained him to tear up anything with writing on it, he consoled himself that this particular paper contained no information of value.
Petunia gasped. Dudley sidled away, in case she started shrieking, and Harry glowered at his cousin. Though they didn't agree about magic, Dudley was at least reasonable about it. Petunia was something of a fanatic.
"But surely," Vernon put in before his wife could get started, "it would be reasonable to learn more about what magic can offer you before writing it off entirely on hearsay?"
"Hah! And waste an entire school year where I might be learning about useful things? Do they even have a mathematics course at Smogwords?"
"Hogwarts," Petunia corrected. "And I believe they do, though they call it something else. Arithma-something."
"Well, that's something at least, but I hardly anticipate them being up to any sort of modern standard. They still write on parchment, for goodness' sake!"
"Expensive parchment," Vernon said, and Harry saw an opening.
"Expensive school," he said slyly. "I know I have a trust fund and everything, but wouldn't it be better to invest that in stocks and business rather than throw it away on some backwards antiquated school for witches?"
"And wizards, like you," Petunia corrected.
Harry rolled his eyes, though he knew it was childish, he couldn't help himself. "It's not like I've memorized every bit of their propaganda, unlike some."
Petunia gasped, affronted, and Harry sighed. "I'm sorry, I don't mean to imply that you're gullible. I know they've put on a good show. But even if magic is real, I can't see any use for it. Otherwise, it would be already in widespread use. It's clearly a useless niche that's going nowhere. I've got to think about my future before deciding to spend half my fortune on an education."
"That's very forward-thinking of you," Vernon said approvingly.
"But, Harry," said Dudley, speaking for the first time. "It's a secret club that no one can talk about without sounding crazy. We know about it, but who else have you ever met who'd even thought of it?"
Harry's next argument died unspoken. He turned to his cousin, tilting his head consideringly.
"Yes, that's a very good point," Petunia hastened to add. "I'm sure if you have concerns with their lack of modern standards, you could be just the catalyst they need to bring their programs up to standard. Especially with your reputation—"
"Don't," Harry warned, anger flaring at the words. "This isn't about my parents. It's about me."
"I didn't mean to imply—" Petunia faltered.
"This is my decision, not theirs. Even assuming your grand stories about their heroics are true, they were the ones who couldn't leave well enough alone. Who weren't willing to stop fighting even though they knew it put them at risk. Put my future at risk. They left me, and don't you dare imply I should be using that stupidity as a popularity stunt. I'm not seven. I don't need them any more."
"But, Harry, dear," Petunia began, but Harry shook his head.
"No. I won't go. You can't make me."
That wasn't the end of it. Of course it wasn't. Letters continued to arrive, one every day, somehow ending up right in Harry's path however he tried to avoid it. He wondered if there were a magical mail-person whose job it was to invent ways to deliver post least intuitively, and how much that person were paid. Such a waste of time and potential.
But he didn't want to reform society. He didn't want to be a rallying cry for change and a new order. All Harry wanted was to work hard like his uncle, earn a place in society like his aunt, and invest wisely in business like his grandparents so that when the time came he could pass on even more to his own children than what he'd been given.
He wanted to very emphatically NOT get mixed up with crazy witch cults with their secret wars and their mysterious disappearances. He wanted to be there for his children, the way Aunt Petunia and Uncle Vernon were there for Dudley and him.
And as much as he believed, secretly in his heart, that magic could be the most powerful, useful, beautiful thing in existence, though he knew that seeking its secrets could give him more than he could ever dream, he remained steadfast in his refusal to be swayed. All the more so, knowing that his own emotions wanted to betray him.
Because this wasn't just about him. It was about who he wanted to be and what he wanted to live for. And in the end, young though he was, attractive though the prospect of waving a stick and flying away to a magical castle might be, his resolve was stronger than the seductive desire of magic.
Harry wouldn't ever be a father who disappeared. He'd be the man who lived.
Author's Note: I wrote this from memory several days after the prompt was posted, so obviously I was a bit off on the particulars, but it was fun and a good way to finish out the year. ;) Happy end-of-2019 y'all! Time to get used to typing 2020 instead.