If you were lucky, you grew up in the generation that was half-raised by the Harry Potter books. If you were even luckier, you had a sister to share Harry Potter with, and the two of you were aggressively nerdy about it together. It's not that there has ever been any dearth of Potterheads in our lives — goodness knows we talked about Harry Potter with our BFFs until our ears just about fell off. But there is something about having a sister who is on the same level of dork as you that just can't be beat. You know that you can tell them anything, with any degree of embarrassing enthusiasm, and they are not only obligated to keep loving you, but already completely and totally understand.
I think of it this way: everybody always says that siblings' voices sound the best together in harmony, since they're raised in the same households and tend to have similar timbres and ways of pronouncing their vowels. Growing up on Harry Potter with someone else by your side is the same way. The way we experience the books is, of course, unique to all of us, but no experience is quite as similar as a pair sisters. That's why anyone with a sister who was a fellow Harry Potter fangirl will relate to all of these way too well:
You probably have vivid memories of your parents reading the books to you together
Aka, the literal only time you didn't fight each other for room under the covers or the fact that you caught her wearing your underwear again ("just turned up in my laundry" my ass), because you were both so mesmerized by the magic that, for the first time, something was more important than one-upping each other.
Going to the book releases together was a BFD
You would deck yourself to the freaking nines — busting out costumes, packing backpacks full of snacks, anxiously waiting at the door together so your poor bedraggled parental units could drive your butts to a bookstore at 11 P.M. on a week night. Together you would stand in line, practically back to back, making sure nobody (god forbid) tried to cut you, lest you have to whip out your wands and Sectumsempra a b*tch. And the moment that book was in your hot little hands, your giddy prepubescent hearts practically beat as one. Which brings me to ...
You always had to buy two books on release night
Your parents learned their lesson the one time they only bought one and you guys tried to "read it together," only to end up clawing each other's eyes out when one of you inevitably sneak-read it after dark and got way ahead of the other.
Halloween was always a fight waiting to happen
I skirted this in my first few years of Harry Potter halloweens — #bless my ginger sister, who always wanted to be Ginny, leaving me to oscillate between Luna and Hermione whenever I pleased. But then my littlest sister started to get into it, and suddenly there was a new human on my nerd turf. Inevitably we always wanted to be the same character. (Could I have been an adult about it? YeeeeaNO. NO. I WAS HERE FIRST AND SHE CAN SUCK A FIZZING WHIZBEE.)
You had very intense opinions about what Houses you each belong in
For instance, my sisters are a Gryffindor and a Slytherin. I am a Hufflepuff. (It's worth mentioning my brother is a Ravenclaw — blame the mailman?) But we changed our minds about this at least 16 times a week growing up, so I do not pity the poor Sorting Hat for having to make the tough decisions.
You were similarly devastated when your Hogwarts letter never came
Even at 13 I was irrationally fearful that one of my little sisters was going to get a letter after I hadn't gotten mine. I LOST SLEEP, GUYS.
One of you introduced the other to the books first, and will be smug about it forever
Like, yeah, it probably only happened because I was the oldest — but that won't stop me from lording it over my sisters' heads until my last dying breath. ("Always," one might even say.)
You definitely dabbled in Harry Potter fan fiction together
What happens in shameless self-insert Mary Sue fan fictions you only ever let your sister read stays in shameless self-insert Mary Sue fan fictions you only ever let your sister read. Nobody will protect your 11-year-old self's screen name (xxomagicgrrrrllllxoxoxox) like your sister does.
Watching the movies every Christmas is more of a tradition than Christmas itself
IDK with all these people pushing Harry Potter marathons during Halloween when this is clearly a December cozy-in-your-jammies, hot cocoa with your sisters kinda series.
You are forever making plans to take trips to Potterworld or PotterCon together
Trust me when I say that there is nobody you'd rather go to a Potter nerdfest with than your sister. You'll be so excited you'll basically want to wet your pants — and sure, your friends understand, but your sister understands. (Or sisters plural, if you, like me, were lucky enough to be flanked by nerds you are blood-related to on a trip to Potterworld.)
No matter how old you get, you'll still occasionally text each other some revelation about the books
Or some link to a Harry Potter article, or something J.K. Rowling has tweeted, or even just a funny GIF. Presented without comment, because duh.
You talked about the characters like they had a spot at the dinner table
In a way, you both let them into your family. You let them into your life. Hermione and Ginny were your honorary sisters. Ron basically was (and, in the case of my ginger bro, is) your brother. Sirius was your fun, slightly unhinged uncle. Hedwig was your pet. It was weird to think they weren't ~real~. You brought them to life together in a way that you never could have alone. And even though you might be all grown up now, it still feels that way whenever you and your sister talk about them, and it always will.
Images: Warner Bros; Giphy