1. Friendship comes out of the most unlikely places.
The book centers not only on Harry, but on the trio formed by him, Ron, and Hermione. And though they were tight-knit, the three of them also gathered a lot of different friends along the way. Everyone from Hagrid to Firenze the centaur, to Luna Lovegood, to Dobby the house-elf turned out to offer the kind of rare, unwavering friendship that is rare in either the muggle or the magical world. You can’t ever discount someone because they’re a little loopy — after all, even Peeves pulled through for Hogwarts in the end.
2. You can be your own worst enemy.
Beyond the fact that Harry was the last of the Horcruxes and therefore had a bit of Voldemort living inside him, there are tons of other instances in which people serve as their own undoings. Wormtail’s magic hand turned on him when he exhibited even a flicker of remorse in the act of killing Harry — it was his guilt that did him in. Crabbe couldn’t escape his own Fiendfyre spell and perished in the room of requirement, and until the end of his life, Snape had to live with the reality that he was the one who enabled the death of the woman he loved. Sometimes, it’s not a matter of going out to seek the evil in this world, as Quirrell did in Albania, but simply recognizing that sometimes there are things in us that will do us in if we’re not brave enough to stand up to ourselves.
3. A first betrayal doesn’t matter as much as what someone does after that counts.
Wormtail betrayed the people who called him a friend, and he never looked back on that choice until the very last seconds of his life. Snape betrayed the woman he grew up with and loved, but devoted the rest of his life to protecting her son — even if he did get a few kicks out of making his life a little hellish. Ron walked out on Harry and Hermione but realized that his proper place was with them and returned. We all make mistakes and regret some of our actions, but being able to admit to these mistakes is what enables us to grow and become better people.
4. Everyone can be a hero in their own way.
The books are full of the most unlikely heroes — Fred and George, who supply a lot of the decoys and magic tricks that help give people upper hands in key elements of the battle; Dobby, who once ran around in a pillow case, but ultimately sacrifices his life for the first wizard to treat him as an equal; and, of course, the glory that is the once-bumbling, plant-loving, endearingly hapless, utterly devoted Neville Longbottom.
5. Telling yourself you’re afraid of something makes it true.
Though Trelawney had a few moments of genuine Sight, a lot of her smoke-and-mirrors prophecy does little more to spook her students. She deeply believes in all the things she’s saying, however, and it wears away at her sanity. And of course, the Wizarding community’s fear of calling Voldemort by his name kept the terror of the man alive – even if they thought he was dead and gone, a lot of people were so accustomed to not saying his name that his legend permeated and kids who hadn’t been born during his reign grew up knowing to be afraid of him. The subsequent taboo only bolstered their fear of him (and not without good reason.) But ultimately, you have to decide how much fear you put into something, and what you’ll do when you finally face those things you’re afraid of.
6. Magic can’t fix everything.
This happens in all things from the practical, because you can’t summon food by magic, to the elaborate. After all, Mirope Gaunt’s love potion doesn’t ensure Tom Riddle Sr. stays in love with her, and the child born of a love spell doesn’t have the ability to experience love the way other people do. Though you could Obliviate people and remove their memories, the feelings will linger — Madam Pomfrey said that thoughts can leave deeper scars than anything else. And as useful as magic might be with household chores and traveling, you can’t expect wars to be over just because one side has magic — after all, as Cornelius Fudge said, that’s not an upper hand when the other side has magic, too. You have to learn instead to rely on the parts of you that aren’t dictated by any special skills — things like grit, perseverance, and trust in other people.
7. An education is important, but it will only get you so far.
Hermione Granger was the smartest witch in her class, but she was so sidetracked by being the best and the smartest that she was often polarized and alienated as being weird. Moreover, throughout all of the books — and especially in the seventh — a lot of what actually helps the kids learn and prepare for the challenges they face is the research they look up on their own, the practice sessions they form as part of Dumbledore’s Army, and the quick thinking that gets them out of countless scrapes when the three of them don’t return to Hogwarts for their final year. (Plus, if ever there was proof that sometimes some school subjects are only as good as the teachers, look at the track record for the Defense Against The Dark Arts position.)
8. You need other people to help complete what you lack.
Everyone has their strengths — Harry’s stubborn bravery, Hermione’s grounded wisdom, Ron’s humor and loyalty, Ginny’s fiercely unapologetic sense of herself, Neville’s devotion, Hagrid’s love for every creature, Dobby’s sense of service… The list goes on and on. And it’s only when these things band together that the characters can accomplish great things. Harry, Ron, and Hermione completed each other the way Moony, Wormtail, Padfoot, and Prongs (and Lily) completed each other. If you’re not that good at something, your friends can help bolster you, teach you how to be better, and keep you afloat when you feel like you’re drowning. It’s not even that you can’t do things without them, but that you shouldn’t want to in the first place.
9. You’re never too old to believe in magic.
Wizards and witches received their letters when they were 11, and children who had grown up in muggle houses were probably taken by surprise because they’d given up the idea that magic existed years ago. But even stepping outside of the books, there’s something so hearteningly wonderful to see a child pick up the books today, or to pick them back up yourself and revisit the friends who you discovered all those years ago, only to realize that the world they inhabit is just as real to you as it ever was.
10. And it’s possible to hold out hope that maybe your owl got lost in the mail.
Even when you’re an adult. That’s totally a really adult thing to do. Because, you never know. If one of the most powerful pieces of magic is love, as Dumbledore says it is, then maybe you and I are magic, after all.