Diagon Quotes

You, and you alone, have reported this mysterious sense of doom. You, and you alone, are a chaos magnet the likes of which I have never seen. After our little shopping trip to Diagon Alley, and then the Sorting Hat, and then today's little episode, I can well foresee that I am fated to sit in the Headmaster's office and hear some hilarious tale about Professor Quirrell in which you and you alone play a starring role, after which there will be no choice but to fire him. I am already resigned to it, Mr. Potter. And if this sad event takes place any earlier than the Ides of May, I will string you up by the gates of Hogwarts with your own intestines and pour fire beetles into your nose. Now do you understand me completely? ~ Eliezer Yudkowsky

Welcome," said Hagrid, "to Diagon Alley. ~ J.K. Rowling

You're mine now, Harry thought at the walls of Diagon Alley, and all the shops and items, and all the shopkeepers and customers; and all the lands and people of wizarding Britain, and all the wider wizarding world; and the entire greater universe of which Muggle scientists understood so much less than they believed. I, Harry James Potter-Evans-Verres, do now claim this territory in the name of Science.
Lightning and thunder completely failed to flash and boom in the cloudless skies.
"What are you smiling about?" inquired Professor McGonagall, warily and wearily.
"I'm wondering if there's a spell to make lightning flash in the background whenever I make an ominous resolution," explained Harry. He was carefully memorising the exact words of his ominous resolution so that future history books would get it right. ~ Eliezer Yudkowsky

Are all your family wizards?" asked Harry, who found Ron just as interesting as Ron found him.
"Er- yes, I think so," said Ron. "I think Mom's got a second cousin who's an accountant, but we never talk about him."
"So you must know loads of magic already."
The Weasleys were clearly one of those old wizarding families the pale boy in Diagon Alley had talked about.
"I heard you went to live with Muggles," said Ron. "What are they like?"
"Horrible- well, not all of them. My aunt and uncle and cousin are, though. Wish I'd had three wizard brothers."
"Five," said Ron. For some reason, he was looking gloomy. "I'm the sixth in our family to go to Hogwarts. You could say I've got a lot to live up to. Bill and Charlie have already left- Bill was head boy and Charlie was captain of Quidditch. Now Percy's a prefect. Fred and George mess around a lot, but they still get really good marks and everyone thinks they're really funny. Everyone expects me to do as well as the others, but if I do, it's no big deal, because they did it first. You never get anything new, either, with five brothers. I've got Bill's old robes, Charlie's old wand, and Percy's old rat."
Ron reached inside his jacket and pulled out a fat gray rat, which was asleep.
"His name's Scabbers and he's useless, he hardly ever wakes up. Percy got an owl from my dad for being made a prefect, but they couldn't aff- I mean, I got Scabbers instead."
Ron's ears went pink. He seemed to thi ~ J.K. Rowling

That left two possibilities, really.
Possibility one: Magic was so incredibly opaque, convoluted, and impenetrable, that even though wizards and witches had tried their best to understand, they'd made little or no progress and eventually given up; and Harry would do no better.
Or ...
Harry cracked his knuckles in determination, but they only made a quiet sort of clicking sound, rather than echoing ominously off the walls of Diagon Alley.
Possibility two: He'd be taking over the world.
Eventually. Perhaps not right away. ~ Eliezer Yudkowsky