As the midway point of the Harry Potter series, Goblet of Fire sees Harry on the cusp of coming of age: while he's described as a boy in the early chapters of the novel, by the end of his fourth year at Hogwarts, Harry finally transitions from a boy to a man. While much of this shift has to do with how Harry and his friends mature personally, even more of it has to do with learning about the wider Wizarding world. Harry and his friends attend the Quidditch World Cup, participate in the Triwizard Tournament (a competition between three European schools of magic), and Harry himself finally sees the Dark Lord Voldemort return to his body--all things that establish Harry as a young adult in the Wizarding world. Taken together, all of this suggests that a natural and essential part of coming of age is discovering one's wider community; exploring that community's history and the ways in which history influences the present; and finally, beginning to think about how one fits into that community.
Harry, Ron, and Hermione's experiences at the Quidditch World Cup illustrate just how young and sheltered all three are in terms of knowing about their world--even though Ron was raised in it. The World Cup exposes the protagonists to a global community of wizards, as well as the wider history of the Wizarding world, which shows the trio what exactly they'll become a part of as they mature and come of age. For Hermione, meeting the house-elf Winky at the World Cup introduces her to some of the less savory parts of the Wizarding world, while Harry is shocked to see that the Wizarding world actually includes the whole world, not just Hogwarts and the UK. He first marvels that it never occurred to him that this would be the case, and after he makes the revelation, he thinks it should've been obvious that there are wizards worldwide.
Ron, on the other hand, introduces the idea that part of growing up and becoming part of the Wizarding world means learning about and grappling with Wizarding history, especially in terms of Voldemort's relatively recent history. When Mr. Weasley herds the trio back to the tent after Voldemort's Dark Mark is sent up into the sky, Ron expresses confusion and says, "it's still only a shape in the sky." As Mr. Weasley goes on to explain, the Dark Mark isn't just "a shape in the sky"--for wizards who remember Voldemort's time of power, it signals death and terror. This is something that, as the novel progresses, Harry and other young people must learn. In doing so, they begin to develop empathy for older generations as well as understand that their world is complex and dangerous--it doesn't end at the Hogwarts boundary, and there is evil in the world that not even Dumbledore can protect them from.
Harry continues to learn about the wider Wizarding world thanks to the Triwizard Tournament, a competition between three European schools--Hogwarts, Durmstrang, and Beauxbatons--that hasn't taken place for years but is resurrected during Harry's fourth year. The tournament directly exposes Harry to students from all over Europe (it's implied that Beauxbatons is a French school, while Durmstrang is located somewhere in Eastern Europe), once again reminding him that the Wizarding world is a global community comprised of people from all walks of life. Dumbledore tells the students outright that the purpose of the competition is to foster international relations and friendship, something he believes is important all the time but is especially important in light of the growing evidence that Voldemort will soon return to power. Indeed, after the Tournament's culmination in which Cedric Diggory, a Hogwarts Champion, is killed by a newly resurrected Voldemort, Dumbledore tells the students that the only effective way to fight Voldemort is by trusting each other and keeping their relationships alive. Voldemort's power stems from his ability to make the Wizarding world feel small, untrustworthy, and isolated, rather than large, supportive, and connected. This suggests that what Harry learns about his larger community over the course of his fourth year directly prepares him to go on to fight Voldemort in the future, and therefore is essential for his coming of age.
In addition to learning about the Wizarding world as a whole, Harry and his classmates also begin to think about what adult life as a wizard in the UK might look like for them. Their examples of what is possible include recent Hogwarts graduate Percy Weasley, who gets his first job as a clerk at the Ministry of Magic over the summer, as well as the two oldest Weasley brothers, Bill (who works for Gringotts Bank) and Charlie (who works with dragons). Professor Moody, noting Harry and Hermione's developing critical thinking skills, suggests that they think about careers as Aurors (Dark Wizard catchers). Fred and George, meanwhile, spend the year developing joke wands and candies with the hope of starting a business selling their goods, and Harry even gives them his Triwizard Tournament winnings to fund the endeavor.
All of these things begin to offer Harry, Hermione, Ron, and the Weasley twins a way to enter into the world, while also reinforcing, especially for young people like Harry and Hermione who didn't grow up in the Wizarding world, that there is a multitude of different ways forward--and not all of them involve the Ministry. When Harry generously gives the Weasley twins his Triwizard winnings, he tells them that their joke shop will be especially needed to provide everyone some comic relief, given Voldemort's return. Harry's comment suggests that he now understands his community's history enough to conceptualize how he and others might become contributing members in their society--especially in one that appears as though it's going to look much like the recent past.
History, Community, and Coming of Age ThemeTracker
History, Community, and Coming of Age Quotes in Harry Potter and the Goblet of Fire
"Those two!" she burst out savagely, now pulling pots and pans out of a cupboard, and Harry knew she meant Fred and George. "I don't know what's going to happen to them, I really don't. No ambition, unless you count making as much trouble as they possibly can..."
Harry laughed but didn't voice the amazement he felt at hearing about other Wizarding schools. He supposed, now that he saw representatives of so many nationalities in the campsite, that he had been stupid never to realize that Hogwarts couldn't be the only one.
"House-elves is not paid, sir!" she said in a muffled squeak. "No, no, no. I says to Dobby, I says, go find yourself a nice family and settle down, Dobby. He is getting up to all sorts of high jinks, sir, what is unbecoming of a house-elf. You goes racketing around like this, Dobby, I says, and next thing I hear you's up in front of the Department for the Regulation and Control of Magical Creatures, like some common goblin."
"I don't get it," said Ron, frowning. "I mean...it's still only a shape in the sky..."
"Ron, You-Know-Who and his followers sent the Dark Mark into the air whenever they killed," said Mr. Weasley. "The terror it inspired...you have no idea, you're too young. Just picture coming home and finding the Dark Mark hovering over your house, and knowing what you're about to find inside..." Mr. Weasley winced. "Everyone's worst fear...the very worst..."
"Now, according to the Ministry of Magic, I'm supposed to teach you countercurses and leave it at that. I'm not supposed to show you what illegal Dark curses look like until you're in the sixth year. You're not supposed to be old enough to deal with it till then. But Professor Dumbledore's got a higher opinion of your nerves, he reckons you can cope, and I say, the sooner you know what you're up against, the better."
"Why are you telling me?" he asked.
Harry looked at him in disbelief. He was sure Cedric wouldn't have asked that if he had seen the dragons himself. Harry wouldn't have let his worst enemy face those monsters unprepared--well, perhaps Malfoy or Snape...
"It's just...fair, isn't it?" he said to Cedric. "We all know now...we're on an even footing, aren't we?"
"He's from Durmstrang!" spat Ron. "He's competing against Harry! Against Hogwarts! You--you're--" Ron was obviously casting around for words strong enough to describe Hermione's crime, "fraternizing with the enemy, that's what you're doing!"
"But what's it matter if his mother was a giantess?" said Harry.
"Well...no one who knows him will care, 'cos they'll know he's not dangerous," said Ron slowly. "But...Harry, they're just vicious, giants. It's like Hagrid said, they're like trolls...they just like killing, everyone knows that."
"What did you bring her for?"
"Fleur didn't turn up, I couldn't leave her," Harry panted.
"Harry, you prat," said Ron, "you didn't take that song thing seriously, did you? Dumbledore wouldn't have let any of us drown!"
"The song said--"
"It was only to make sure you got back inside the time limit!" said Ron. "I hope you didn't waste time down there acting the hero!"
Harry felt both stupid and annoyed. It was all very well for Ron; he'd been asleep, he hadn't felt how eerie it was down in the lake, surrounded by spear-carrying merpeople who'd looked more than capable of murder.
As Harry took off his glasses and climbed into his four-poster, he imagined how it must feel to have parents still living but unable to recognize you. He often got sympathy from strangers for being an orphan, but as he listened to Neville's snores, he thought that Neville deserved it more than he did.
"The second step you must take--and at once," Dumbledore pressed on, "is to send envoys to the giants."
"Envoys to the giants?" Fudge shrieked, finding his tongue again. "What madness is this?"
"Extend the hand of friendship, now, before it is too late," said Dumbledore, "or Voldemort will persuade them, as he did before, that he alone among wizards will give them their rights and their freedom!"
"I say to you all, once again--in the light of Lord Voldemort's return, we are only as strong as we are united, as weak as we are divided. Lord Voldemort's gift for spreading discord and enmity is very great. We can fight it only by showing an equally strong bond of friendship and trust. Differences of habit and language are nothing at all if our aims are identical and our hearts are open."