Of course, there was no such thing as a midnight Harry Potter party when the first book in J.K. Rowling’s Harry Potter series was released in the United States back in 1998. I was a bookseller at a Borders when Harry Potter and the Sorcerer’s Stone debuted, and the books gradually gained attention thanks to a word-of-mouth campaign spurred by the book’s popularity in Britain and a succession of breathless media reports ranging from newspapers to NPR to daytime talk shows.

By the time the final book in the series, Harry Potter and the Deathly Hallows, was released in 2007, the midnight release party had become a beloved ritual for a whole generation of kids. They grew up with the books, and every new release in the series brought with it an ever-increasingly more elaborate series of bookstore events. Booksellers dressed up like wizards. Kids participated in raffles and trivia contests and ate snacks lifted from the novels.

The Harry Potter party craze couldn’t have arrived at a more fortuitous time for the publishing industry. Even as Amazon’s popularity seemed to increase exponentially with each passing year, independent bookstores gently trained a whole new generation of kids to look forward to congregating at bookshops with other book nerds. For once, the passive pleasure of discovering a brown cardboard parcel on your doorstep paled in comparison with the pageantry of actually visiting an actual bookstore staffed with actual human beings.

And now is the time for this generation of twentysomethings to wallow in the kind of nostalgia that has suffocated every American generation before it. The latest in the Harry Potter series, a play titled Harry Potter and the Cursed Child co-written by J.K. Rowling, is being released at midnight on Sunday, July 31st—Harry Potter’s canonical birthday—and both University Book Store and Elliott Bay Book Company are hosting release parties for millennials to relive the good old days. Festivities at Elliott Bay begin at 10 pm on Saturday, July 30 and continue well past midnight on the 31st. University Book Store's party starts at 11 am on the 31st.

Both stores are hosting performances of excerpts of the new play by local theater troupes. University Book Store promises birthday cake and other treats. Elliott Bay is acknowledging the advanced age of the Harry Potter demographic by promising (presumably alcoholic) “Hogsmeade libations,” a trivia contest, and what sounds like a Potter-themed drinking game.

It’s hard to think of many other characters who have been allowed to age with an audience like this. Sue Townsend’s Adrian Mole books come to mind as peers of Potter, but for the most part, kids’ book characters like Nancy Drew and the Magic School Bus kids stay young forever, trapped in a permanent, moisturized fog. Unlike most relationships between readers and favorite fictional characters, this devotion is so strong that it takes up physical space in the world every few years. It makes you wonder if one day a generation of weeping, middle-aged adults will gather at bookstores around the world to show their respect at a funeral for a lifelong friend.