Harry Potter and the Sorcerer's Stone
The Supernatural Quotes
How we cite our quotes:
He turned to smile at the tabby, but it had gone. Instead he was smiling at a rather severe-looking woman who was wearing square glasses exactly the shape of the markings the cat had had around its eyes. (1.47)
Rowling doesn't waste any time – we're only partway through chapter one and we've already witnessed our first Transfiguration. Here McGonagall transforms from a tabby cat into her real form – professor at Hogwarts. From context given later in the book, we know how hard just transforming a match into a needle is: given the ease with which McGonagall goes from cat to person, she must be a very powerful witch indeed.
"I'm a what?" gasped Harry.
"A wizard, o' course," said Hagrid, sitting back down on the sofa, which groaned and sank even lower, "an' a thumpin' good 'un, I'd, say, once yeh've been trained up a bit. With a mum an' dad like yours, what else would yeh be?" (4.63-64)
For Harry – and, we might imagine, anyone who's grown up only knowing about Muggles – learning that there's not only magic and wizards, but that he himself is one, comes as a pretty big shock. It's not just finding out that supernatural elements exist, it's discovering that he's one of those supernatural elements himself.
"Wizards have banks?"
"Just the one. Gringotts. Run by goblins."
Harry dropped the bit of sausage he was holding.
We're not sure what's more of a shock here: 1) the idea that "wizards have banks," just like non-wizards do, and that they would still value currency the way non-wizards do; or 2) that there are "goblins" in this world, and that they work at the wizard bank. For Hagrid, of course, who's grown up in this magical realm, it's just a matter of course. And really, for Harry, it shouldn't be too much of a stretch to start believing in goblins, when he's already been convinced about wizards.